Lubricant compositions including alpha-olefin copolymers

ABSTRACT

A lubricant composition may include a copolymer having constitutional units formed from monomers including an alpha-olefin and an α-ester-alk-ω-ene molecule, where the composition has a kinematic viscosity at 100° C. of at most 20 centistokes, or of at least 40 centistokes. A lubricant composition may include a copolymer having constitutional units formed from monomers including an alpha-olefin, an α-ester-alk-ω-ene molecule and an α-(carboxylic acid)-alk-ω-ene molecule, where the composition has a viscosity that varies as the molar ratio of the α-ester-alk-ω-ene molecule α-(carboxylic acid)-alk-ω-ene molecule in the monomers varies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/783,083, filed Mar. 14, 2013, the entire contents of which are herebyincorporated by reference.

BACKGROUND

Lubricants are compositions that reduce friction between surfaces. Inaddition to allowing freedom of motion between two surfaces and reducingmechanical wear of the surfaces, a lubricant also may inhibit corrosionof the surfaces and/or may inhibit damage to the surfaces due to heat oroxidation. Examples of lubricant compositions include, but are notlimited to, motor oils, transmission fluids, gear oils, industriallubricating oils, and metalworking oils.

A typical lubricant composition includes a base oil and optionally oneor more additives. Conventional base oils are hydrocarbons, such asmineral oils. A wide variety of additives may be combined with the baseoil, depending on the intended use of the lubricant. Examples oflubricant additives include, but are not limited to, oxidationinhibitors, corrosion inhibitors, dispersing agents, high pressureadditives, anti-foaming agents and metal deactivators.

The physical and chemical properties of a lubricant are affected by thechemical structures of the various components of the lubricant, therelative amounts of the components in the lubricant, and the processingtechniques used to form the lubricant. For example, the chemicalstructure of the base oil may determine overall ranges of physical andchemical properties of the lubricant, with the specific properties beingaffected by the other components of the lubricant composition and/or themanner in which the lubricant composition is prepared. Alteration of thechemical structure of the base oil can allow for modification of theoverall range of properties of a lubricant containing the base oil.

One potential approach to altering the chemical structure of a lubricantcomponent, including the chemical structure of a base oil, is to formthe component from a renewable feedstock. Renewable feedstocks, such asfatty acids or fatty esters derived from natural oils, have opened newpossibilities for the development of a variety of industrially usefulsubstances, including lubricants. For example, renewable feedstocks canbe used to prepare lubricants having combinations of properties thatwere not available with conventional petroleum feedstocks. In anotherexample, renewable feedstocks can be used to prepare lubricants moreefficiently, without requiring undesirable reagents or solvents, and/orwith decreased amounts of waste or side products.

It would be desirable to provide lubricant compositions that includecomponents having new chemical structures. Preferably such compositionscan provide acceptable lubricant performance, while having an increasedconcentration of components formed from renewable feedstocks. Preferablysuch compositions can provide useful combinations of lubricantproperties that are difficult to obtain using only conventionalpetroleum feedstocks.

SUMMARY

The scope of the present invention is defined solely by the appendedclaims, and is not affected to any degree by the statements within thissummary.

In one aspect, a lubricant composition is provided that includes acopolymer including constitutional units formed from monomers includingan alpha-olefin and an α-ester-alk-ω-ene molecule. The composition has akinematic viscosity at 100° C. of at most 20 centistokes (milliPascalsecond)s.

In another aspect, a lubricant composition is provided that includes acopolymer including constitutional units formed from monomers includingan alpha-olefin, an α-ester-alk-ω-ene molecule, and an α-(carboxylicacid)-alk-ω-ene molecule. The composition has a kinematic viscosity at100° C. that varies from 15 centistokes to 35 centistokes as the molarratio of the α-ester-alk-ω-ene molecule to the α-(carboxylicacid)-alk-ω-ene molecule in the monomers varies from 99.9:0.1 to0.1:99.9.

In another aspect, a lubricant composition is provided that includes acopolymer including constitutional units formed from monomers includingan alpha-olefin and an α-ester-alk-ω-ene molecule. The composition has akinematic viscosity at 100° C. of at least 40 centistokes.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale and are not intended to accurately representmolecules or their interactions, emphasis instead being placed uponillustrating the principles of the invention. Moreover, in the figures,like referenced numerals designate corresponding parts throughout thedifferent views.

FIG. 1 represents a method of making a lubricant composition.

FIG. 2 depicts a representative reaction scheme for a method of forminga copolymer.

FIG. 3 depicts graphs of copolymer molecular weights and ofpolydispersity indices (PDI) as a function of di-t-amyl peroxideinitiator loading.

FIG. 4 depicts graphs of copolymer yield and of kinematic viscosity (KV)at 100° C. as a function of di-t-amyl peroxide initiator loading.

FIG. 5 depicts graphs of copolymer yield and of kinematic viscosity (KV)at 100° C. as a function of di-t-butyl peroxide initiator loading.

FIG. 6 depicts graphs of copolymer yield and of kinematic viscosity (KV)at 100° C. as a function of 9-DAME loading.

FIG. 7 depicts a graph of copolymer viscosity as a function of reactionyield for copolymerizations conducted with and without a chain transferagent.

FIG. 8 depicts a graph of copolymer viscosity as a function ofdi-t-butyl peroxide initiator loading at reaction temperatures of 155°C. and 165° C.

DETAILED DESCRIPTION

To provide a clear and more consistent understanding of thespecification and claims of this application, the following definitionsare provided.

The term “polymer” refers to a substance having a chemical structurethat includes the multiple repetition of constitutional units formedfrom substances of comparatively low relative molecular mass relative tothe molecular mass of the polymer. The term “polymer” includes solubleand/or fusible molecules having chains of repeat units, and alsoincludes insoluble and infusible networks.

The term “monomer” refers to a substance that can undergo apolymerization reaction to contribute constitutional units to thechemical structure of a polymer.

The term “copolymer” refers to a polymer having constitutional unitsformed from more than one species of monomer. The definitions for“polymer”, “monomer” and “copolymer” are derived from IUPAC, Pure Appl.Chem., Vol. 68, No. 8, pp. 1591-1595, 1996.

The terms “reaction” and “chemical reaction” refer to the conversion ofa substance into a product, irrespective of reagents or mechanismsinvolved.

The term “reaction product” refers to a substance produced from achemical reaction of one or more reactant substances.

The term “yield” refers to the amount of reaction product formed in areaction. When expressed with units of percent (%), the term yieldrefers to the amount of reaction product actually formed, as apercentage of the amount of reaction product that would be formed if allof the reactant were converted into the product.

The term “alkyl group” refers to a group formed by removing a hydrogenfrom a carbon of an alkane, where an alkane is an acyclic or cycliccompound consisting entirely of hydrogen atoms and saturated carbonatoms.

The term “alkenyl group” refers to a group formed by removing a hydrogenfrom a carbon of an alkene, where an alkene is an acyclic or cycliccompound consisting entirely of hydrogen atoms and carbon atoms, andincluding at least one carbon-carbon double bond.

The term “metathesis catalyst” refers to any catalyst or catalyst systemconfigured to catalyze a metathesis reaction.

The terms “metathesize” and “metathesizing” refer to a chemical reactioninvolving a single type of olefin or a plurality of different types ofolefin, which is conducted in the presence of a metathesis catalyst, andwhich results in the formation of at least one new olefin product. Thephrase “metathesis reaction” encompasses cross-metathesis (a.k.a.co-metathesis), self-metathesis, ring-opening metathesis (ROM),ring-opening metathesis polymerizations (ROMP), ring-closing metathesis(RCM), and acyclic diene metathesis (ADMET), and the like, andcombinations thereof.

The terms “natural oils,” “natural feedstocks,” or “natural oilfeedstocks” mean oils derived from plants or animal sources. The term“natural oil” includes natural oil derivatives, unless otherwiseindicated. The terms also include modified plant or animal sources(e.g., genetically modified plant or animal sources), unless indicatedotherwise. Examples of natural oils include but are not limited tovegetable oils, algal oils, animal fats, tall oils, derivatives of theseoils, combinations of any of these oils, and the like. Examples ofvegetable oils include but are not limited to canola oil, rapeseed oil,coconut oil, corn oil, cottonseed oil, olive oil, palm oil, peanut oil,safflower oil, sesame oil, soybean oil, sunflower oil, linseed oil, palmkernel oil, tung oil, jatropha oil, mustard oil, camelina oil,pennycress oil, castor oil, and the like, and combinations thereof.Examples of animal fats include but are not limited to lard, tallow,poultry fat, yellow grease, fish oil, and the like, and combinationsthereof. Tall oils are by-products of wood pulp manufacture. A naturaloil may be refined, bleached, and/or deodorized.

The term “natural oil derivatives” refers to compounds or mixtures ofcompounds derived from one or more natural oils using any one orcombination of methods known in the art. Such methods include but arenot limited to saponification, transesterification, esterification,hydrogenation (partial or full), isomerization, oxidation, reduction,and the like, and combinations thereof. Examples of natural oilderivatives include but are not limited to gums, phospholipids,soapstock, acidulated soapstock, distillate or distillate sludge, fattyacids such as oleic acid, fatty acid alkyl esters such as methyl oleateand 2-ethylhexyl ester, hydroxy-substituted variations of the naturaloil, and the like, and combinations thereof. For example, the naturaloil derivative may be a fatty acid methyl ester (FAME) derived from theglyceride of the natural oil.

The term “metathesized natural oil” refers to the metathesis reactionproduct of a natural oil in the presence of a metathesis catalyst, wherethe metathesis product includes a new olefinic compound. A metathesizednatural oil may include a reaction product of two triglycerides in anatural feedstock (self-metathesis) in the presence of a metathesiscatalyst, where each triglyceride has an unsaturated carbon-carbondouble bond, and where the reaction product includes a “natural oiloligomer” having a new mixture of olefins and esters that may includeone or more of metathesis monomers, metathesis dimers, metathesistrimers, metathesis tetramers, metathesis pentamers, and higher ordermetathesis oligomers (e.g., metathesis hexamers). A metathesized naturaloil may include a metathesis reaction product of a natural oil thatincludes more than one source of natural oil (e.g., a mixture of soybeanoil and palm oil). A metathesized natural oil may include a metathesisreaction product of a natural oil that includes a mixture of naturaloils and natural oil derivatives. A metathesized natural oil may includea cross-metathesis reaction product of a natural oil with anothersubstance having a carbon-carbon double bond, such as an olefin orethylene.

A lubricant composition may be formed from a renewable feedstock, suchas a renewable feedstock formed through metathesis reactions of naturaloils and/or their fatty acid or fatty ester derivatives. When compoundscontaining a carbon-carbon double bond undergo metathesis reactions inthe presence of a metathesis catalyst, some or all of the originalcarbon-carbon double bonds are broken, and new carbon-carbon doublebonds are formed. The products of such metathesis reactions includecarbon-carbon double bonds in different locations, which can provideunsaturated organic compounds having useful chemical structures.

Renewable feedstocks for lubricants may include unsaturated compoundshaving a polymerizable carbon-carbon double bond. These unsaturatedcompounds may be used as monomers or as comonomers in polymerizationreactions, to provide higher molecular weight substances that can beused as a lubricant base oil or additive. The unsaturated compounds maybe polymerized alone to form homopolymers, or they may be polymerizedwith other comonomers to form copolymers. Other comonomers may includesubstances formed from conventional petrochemical feedstocks.

A lubricant composition may include a copolymer including constitutionalunits formed from an alpha-olefin monomer and an α-ester-alk-ω-enemonomer, where the α-ester-alk-ω-ene monomer is derived from ametathesized natural oil. The use of a monomer containing a metathesizednatural oil derivative can provide additional options for preparinglubricant compositions having useful combinations of properties,including but not limited to low viscosity, high viscosity, viscositythat can be varied from low to high, oxidative stability, thermalstability, and hydrolytic stability. The use of a monomer containing ametathesized natural oil derivative also may provide certain advantagesover commercial lubricants, including but not limited to simpler and/ormore cost-effective production, reduced variability, improved sourcing,and increased biorenewability.

A lubricant composition includes a copolymer including constitutionalunits formed from monomers, including a first monomer that is analpha-olefin, and a second monomer that is an α-ester-alk-ω-enemolecule. Preferably the lubricant composition has a kinematic viscosityat 100° C. of at most 20 centistokes (cSt), or of at least 40 cSt. Thelubricant composition may be a low-viscosity composition having akinematic viscosity at 100° C. of at most 20 cSt, including from 5 to 20cSt and from 10 to 15 cSt. The lubricant composition may be ahigh-viscosity composition having a kinematic viscosity at 100° C. of atleast 40 cSt, including from 40 to 100 cSt and from 40 to 60 cSt. Thelubricant composition may be a variable-viscosity composition having akinematic viscosity at 100° C. that varies from 15 to 35 cSt as theratio of the α-ester-alk-ω-ene molecule to the α-(carboxylicacid)-alk-ω-ene molecule in the monomers varies from 99.9:0.1 to0.1:99.9.

FIG. 1 represents a method 100 of making a lubricant composition. Themethod 100 includes forming 101 a reaction mixture 110 containing afirst monomer 112 that is an alpha-olefin, a second monomer 114 that isan α-ester-alk-ω-ene molecule, and optionally at least one other monomer116; forming 102 a product mixture 120 containing a copolymer 122 havingconstitutional units formed from the monomers 112, 114 and optionally116; and optionally combining 103 the copolymer 122 with at least oneother material 130.

The alpha-olefin monomer 112 may include any hydrocarbon having a chainof at least 3 carbon atoms and an alkenyl group positioned at the end ofthe chain. The alpha-olefin monomer may be represented by the structureH₂C═C(R¹)(R²), where R¹ is a first hydrocarbon group, and R² is eitherhydrogen or a second hydrocarbon group. When R¹ and R² are each ahydrocarbon group, R¹ and R² may be the same or they may be different.If R¹ and/or R² include 3 or more carbon atoms, R¹ and R² independentlymay include a straight chain of the carbon atoms or may include abranched chain.

Examples of mono-substituted alpha-olefin monomers, in which R² ishydrogen, include but are not limited to linear alpha-olefins such aspropene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene,1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadeceneand 1-eicosene. Examples of mono-substituted alpha-olefin monomersinclude but are not limited to branched alpha-olefins such assubstituted derivatives of 1-butene, 1-pentene, 1-hexene, 1-heptene,1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene,1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene,1-nonadecene or 1-eicosene, where the substituted derivative issubstituted at a saturated carbon with one or more hydrocarbon groupshaving from one to 10 carbon atoms.

Examples of di-substituted alpha-olefin monomers, in which R² is ahydrocarbon group, include but are not limited to isobutylene,2-methylbut-1-ene, 2-methylpent-1-ene, 2-methylhex-1-ene,2-methylhept-1-ene, 2-methyloct-1-ene, and the like; 2-ethylbut-1-ene,2-ethylpent-1-ene, 2-ethylhex-1-ene, 2-ethylhept-1-ene,2-ethyloct-1-ene, and the like; 2-propylpent-1-ene, 2-propylhex-1-ene,2-propylhept-1-ene, 2-propyloct-1-ene, and the like; and2-butylhex-1-ene, 2-butylhept-1-ene, 2-butyloct-1-ene, and the like.

The α-ester-alk-ω-ene monomer 114 has the chemical formulaR³—O—C(═O)—(R⁴)—CH═CH₂, where R³ is a alkyl group having from 1 to 5carbon atoms, and R⁴ is an alkyl group having from 2 to 20 carbon atoms.Examples of α-ester-alk-ω-ene molecules include but are not limited to9-decenoic acid methyl ester, 9-decenoic acid ethyl ester, 9-decenoicacid propyl ester, 9-decenoic acid butyl ester, 9-decenoic acid pentylester, 10-undecenoic acid methyl ester, 10-undecenoic acid ethyl ester,10-undecenoic acid propyl ester, 11-dodecenoic acid methyl ester,11-dodecenoic acid ethyl ester, and 11-dodecenoic acid propyl ester.

The α-ester-alk-ω-ene monomer 114 may be the product of a metathesisreaction of a natural oil, a natural oil derivative or a metathesizednatural oil in the presence of a metathesis catalyst. The metathesiscatalyst in this reaction may include any catalyst or catalyst systemthat catalyzes a metathesis reaction. Any known metathesis catalyst maybe used, alone or in combination with one or more additional catalysts.Examples of metathesis catalysts and process conditions are described inparagraphs [0069]-[0155] of US 2011/0160472, incorporated by referenceherein in its entirety, except that in the event of any inconsistentdisclosure or definition from the present specification, the disclosureor definition herein shall be deemed to prevail. A number of themetathesis catalysts described in US 2011/0160472 are presentlyavailable from Materia, Inc. (Pasadena, Calif.).

In some embodiments, the metathesis catalyst includes a transitionmetal. In some embodiments, the metathesis catalyst includes ruthenium.In some embodiments, the metathesis catalyst includes rhenium. In someembodiments, the metathesis catalyst includes tantalum. In someembodiments, the metathesis catalyst includes nickel. In someembodiments, the metathesis catalyst includes tungsten. In someembodiments, the metathesis catalyst includes molybdenum.

In some embodiments, the metathesis catalyst includes a rutheniumcarbene complex and/or an entity derived from such a complex. In someembodiments, the metathesis catalyst includes a material selected fromthe group consisting of a ruthenium vinylidene complex, a rutheniumalkylidene complex, a ruthenium methylidene complex, a rutheniumbenzylidene complex, and combinations thereof, and/or an entity derivedfrom any such complex or combination of such complexes. In someembodiments, the metathesis catalyst includes a ruthenium carbenecomplex comprising at least one phosphine ligand and/or an entityderived from such a complex. In some embodiments, the metathesiscatalyst includes a ruthenium carbene complex comprising at least onetricyclohexylphosphine ligand and/or an entity derived from such acomplex. In some embodiments, the metathesis catalyst includes aruthenium carbene complex comprising at least two tricyclohexylphosphineligands [e.g., (PCy₃)₂Cl₂Ru=CH—CH═C(CH₃)₂, etc.] and/or an entityderived from such a complex. In some embodiments, the metathesiscatalyst includes a ruthenium carbene complex comprising at least oneimidazolidine ligand and/or an entity derived from such a complex. Insome embodiments, the metathesis catalyst includes a ruthenium carbenecomplex comprising an isopropyloxy group attached to a benzene ringand/or an entity derived from such a complex.

In some embodiments, the metathesis catalyst includes a Grubbs-typeolefin metathesis catalyst and/or an entity derived therefrom. In someembodiments, the metathesis catalyst includes a first-generationGrubbs-type olefin metathesis catalyst and/or an entity derivedtherefrom. In some embodiments, the metathesis catalyst includes asecond-generation Grubbs-type olefin metathesis catalyst and/or anentity derived therefrom. In some embodiments, the metathesis catalystincludes a first-generation Hoveda-Grubbs-type olefin metathesiscatalyst and/or an entity derived therefrom. In some embodiments, themetathesis catalyst includes a second-generation Hoveda-Grubbs-typeolefin metathesis catalyst and/or an entity derived therefrom. In someembodiments, the metathesis catalyst includes one or a plurality of theruthenium carbene metathesis catalysts sold by Materia, Inc. ofPasadena, Calif. and/or one or more entities derived from suchcatalysts. Representative metathesis catalysts from Materia, Inc. foruse in accordance with the present teachings include but are not limitedto those sold under the following product numbers as well ascombinations thereof: product no. C823 (CAS no. 172222-30-9), productno. C848 (CAS no. 246047-72-3), product no. C601 (CAS no. 203714-71-0),product no. C627 (CAS no. 301224-40-8), product no. C571 (CAS no.927429-61-6), product no. C598 (CAS no. 802912-44-3), product no. C793(CAS no. 927429-60-5), product no. C801 (CAS no. 194659-03-9), productno. C827 (CAS no. 253688-91-4), product no. C884 (CAS no. 900169-53-1),product no. C833 (CAS no. 1020085-61-3), product no. C859 (CAS no.832146-68-6), product no. C711 (CAS no. 635679-24-2), product no. C933(CAS no. 373640-75-6).

In some embodiments, the metathesis catalyst includes a molybdenumand/or tungsten carbene complex and/or an entity derived from such acomplex. In some embodiments, the metathesis catalyst includes aSchrock-type olefin metathesis catalyst and/or an entity derivedtherefrom. In some embodiments, the metathesis catalyst includes ahigh-oxidation-state alkylidene complex of molybdenum and/or an entityderived therefrom. In some embodiments, the metathesis catalyst includesa high-oxidation-state alkylidene complex of tungsten and/or an entityderived therefrom. In some embodiments, the metathesis catalyst includesmolybdenum (VI). In some embodiments, the metathesis catalyst includestungsten (VI). In some embodiments, the metathesis catalyst includes amolybdenum- and/or a tungsten-containing alkylidene complex of a typedescribed in one or more of (a) Angew. Chem. Int. Ed. Engl., 2003, 42,4592-4633; (b) Chem. Rev., 2002, 102, 145-179; and/or (c) Chem. Rev.,2009, 109, 3211-3226, each of which is incorporated by reference hereinin its entirety, except that in the event of any inconsistent disclosureor definition from the present specification, the disclosure ordefinition herein shall be deemed to prevail.

Metathesis is a catalytic reaction that involves the interchange ofalkylidene units among compounds containing one or more double bonds(i.e., olefinic compounds) via the formation and cleavage of thecarbon-carbon double bonds. The α-ester-alk-ω-ene molecule 114 may beformed by a metathesis reaction of a natural oil containing unsaturatedpolyol esters, including a cross-metathesis reaction of a natural oil ora natural oil derivative with an alpha-olefin or with ethylene. Theα-ester-alk-ω-ene molecule 114 may be formed by a metathesis reaction ofa metathesized natural oil containing unsaturated polyol esters,including a cross-metathesis reaction of a metathesized natural oil withan alpha-olefin or with ethylene. Examples of cross-metathesis reactionsof natural oils, natural oil derivatives and/or of metathesized naturaloils that can produce substances including terminal alkenyl groups aredescribed in US 2010/0145086 and in US 2012/0071676, which areincorporated by reference herein in their entirety, except that in theevent of any inconsistent disclosure or definition from the presentspecification, the disclosure or definition herein shall be deemed toprevail.

Examples of natural oils include but are not limited to vegetable oil,algal oil, animal fat, tall oil, derivatives of these oils, or mixturesthereof. Examples of vegetable oils include but are not limited tocanola oil, rapeseed oil, coconut oil, corn oil, cottonseed oil, oliveoil, palm oil, peanut oil, safflower oil, sesame oil, soybean oil,sunflower oil, linseed oil, palm kernel oil, tung oil, jatropha oil,mustard oil, camelina oil, pennycress oil, castor oil, and the like, andcombinations thereof. Examples of animal fats include but are notlimited to lard, tallow, poultry fat, yellow grease, fish oil, and thelike, and combinations thereof. Examples of natural oil derivativesinclude but are not limited to metathesis oligomers, gums,phospholipids, soapstock, acidulated soapstock, distillate or distillatesludge, fatty acids and fatty acid alkyl ester such as 2-ethylhexylester, hydroxyl-substituted variations of the natural oil, and the like,and combinations thereof. For example, the natural oil derivative may bea fatty acid methyl ester (FAME) derived from the glyceride of thenatural oil.

The natural oil may include canola or soybean oil, such as refined,bleached and deodorized soybean oil (i.e., RBD soybean oil). Soybean oiltypically includes about 95 percent by weight (wt %) or greater (e.g.,99 wt % or greater) triglycerides of fatty acids. Major fatty acids inthe polyol esters of soybean oil include but are not limited tosaturated fatty acids such as palmitic acid (hexadecanoic acid) andstearic acid (octadecanoic acid), and unsaturated fatty acids such asoleic acid (9-octadecenoic acid), linoleic acid (9,12-octadecadienoicacid), and linolenic acid (9,12,15-octadecatrienoic acid).

Examples of metathesized natural oils include but are not limited to ametathesized vegetable oil, a metathesized algal oil, a metathesizedanimal fat, a metathesized tall oil, a metathesized derivatives of theseoils, or mixtures thereof. For example, a metathesized vegetable oil mayinclude metathesized canola oil, metathesized rapeseed oil, metathesizedcoconut oil, metathesized corn oil, metathesized cottonseed oil,metathesized olive oil, metathesized palm oil, metathesized peanut oil,metathesized safflower oil, metathesized sesame oil, metathesizedsoybean oil, metathesized sunflower oil, metathesized linseed oil,metathesized palm kernel oil, metathesized tung oil, metathesizedjatropha oil, metathesized mustard oil, metathesized camelina oil,metathesized pennycress oil, metathesized castor oil, metathesizedderivatives of these oils, or mixtures thereof. In another example, themetathesized natural oil may include a metathesized animal fat, such asmetathesized lard, metathesized tallow, metathesized poultry fat,metathesized fish oil, metathesized derivatives of these oils, ormixtures thereof.

The α-ester-alk-ω-ene molecule 114 may be formed by a cross-metathesisreaction of a natural oil, a natural oil derivative and/or ametathesized natural oil containing unsaturated polyol esters with anorganic compound containing a terminal alkenyl group, or with ethylene.An organic compound containing a terminal alkenyl group is a compoundhaving an alkene group, where a first carbon of the alkene group isunsubstituted and a second carbon of the alkene group is substitutedwith one or two non-hydrogen substituents. The compound may include from3 to about 20 carbon atoms, about 10 carbon atoms, about 6 carbon atoms,or about 3 carbon atoms. A cross-metathesis reaction may involve asingle species of the compound containing a terminal alkenyl group, orit may involve a mixture of such species of the compound.

As an example, a compound containing a terminal alkenyl group for use incross-metathesis may have the structure H₂C═C(R⁵)(R⁶), where R⁵ and R⁶are independently hydrogen, a hydrocarbon group, or a heteroalkyl group,provided that at least one of R⁵ and R⁶ is not hydrogen. The heteroatomsof a heteroalkyl group may be present as part of a functional groupsubstituent. R⁵ and R⁶ may be linked to form a cyclic structure. In apreferred embodiment, R⁵ and R⁶ are independently selected from C₁-C₂₀alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₁-C₂₀ heteroalkyl, C₂-C₂₀heteroalkenyl, C₂-C₂₀ heteroalkynyl, C₅-C₂₄ aryl, C₆-C₂₄ alkylaryl,C₆-C₂₄ arylalkyl, C₅-C₂₄ heteroaryl, and C₆-C₂₄ heteroalkylaryl, C₆-C₂₄heteroarylalkyl.

Examples of monosubstituted compounds containing a terminal alkenylgroup that may be used in cross-metathesis include 1-propene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene,1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene andlarger alpha-olefins; 2-propenol, 3-butenol, 4-pentenol, 5-hexenol,6-heptenol, 7-octenol, 8-nonenol, 9-decenol, 10-undecenol, 11-dodecenol,12-tridecenol, 13-tetradecenol, 14-pentadecenol, 15-hexadecenol,16-heptadecenol, 17-octadecenol, 18-nonadecenol, 19-eicosenol and largeralpha-alkenols; 2-propenyl acetate, 3-butenyl acetate, 4-pentenylacetate, 5-hexenyl acetate, 6-heptenyl acetate, 7-octenyl acetate,8-nonenyl acetate, 9-decenyl acetate, 10-undecenyl acetate, 11-dodecenylacetate, 12-tridecenyl acetate, 13-tetradecenyl acetate, 14-pentadecenylacetate, 15-hexadecenyl acetate, 16-heptadecenyl acetate, 17-octadecenylacetate, 18-nonadecenyl acetate, 19-eicosenyl acetate and largeralpha-alkenyl acetates; 2-propenyl chloride, 3-butenyl chloride,4-pentenyl chloride, 5-hexenyl chloride, 6-heptenyl chloride, 7-octenylchloride, 8-nonenyl chloride, 9-decenyl chloride, 10-undecenyl chloride,11-dodecenyl chloride, 12-tridecenyl chloride, 13-tetradecenyl chloride,14-pentadecenyl chloride, 15-hexadecenyl chloride, 16-heptadecenylchloride, 17-octadecenyl chloride, 18-nonadecenyl chloride, 19-eicosenylchloride and larger alpha-alkenyl chlorides, bromides, and iodides;allyl cyclohexane, allyl cyclopentane; and the like. Examples ofdisubstituted compounds containing a terminal alkenyl group that may beused in cross-metathesis include isobutylene, 2-methylbut-1-ene,2-methylpent-1-ene, 2-methylhex-1-ene, 2-methylhept-1-ene,2-methyloct-1-ene, and the like.

Any combination of any of these compounds containing a terminal alkenylgroup may be used in a cross-metathesis reaction with a natural oil, anatural oil derivative and/or a metathesized natural oil containingunsaturated polyol esters, to provide the α-ester-alk-ω-ene molecule114. In an exemplary embodiment, a composition including 9-DAME, whichis an α-ester-alk-ω-ene molecule, can be prepared by thecross-metathesis of 1-propene with a natural oil, a natural oilderivative and/or a metathesized natural oil containing unsaturatedpolyol esters. For example, oleic acid and/or methyl oleate may undergocross-metathesis with 1-propene to provide a composition including9-DAME. Due to the stoichiometry of the cross-metathesis reaction, theproduct composition typically includes about 50 mole percent (mol %)9-DAME and about 50 mol % 9-undecenoic acid methyl ester.

Ethylene also may be used in a cross-metathesis reaction with a naturaloil, a natural oil derivative and/or a metathesized natural oilcontaining unsaturated polyol esters, to provide the α-ester-alk-ω-enemolecule 114. In an exemplary embodiment, a composition including9-DAME, which is an α-ester-alk-ω-ene molecule, can be prepared by thecross-metathesis of ethylene with a natural oil and/or a metathesizednatural oil containing unsaturated polyol esters. For example, methyloleate may undergo cross-metathesis with ethylene to provide acomposition including 9-DAME. Due to the stoichiometry of thecross-metathesis reaction, the product composition typically includesabout 50 mol % 9-DAME and about 50 mol % 1-decene.

The optional at least one other monomer 116 may include anypolymerizable substance that contains an alkenyl group. Examples of suchunsaturated polymerizable substances include the alpha-alkenols,alpha-alkenyl acetates, alpha-alkenyl halides (chlorides, bromides oriodides), allyl cyclohexane and allyl cyclopentane described above withregard to the monosubstituted compounds containing a terminal alkenylgroup for cross-metathesis. Examples of such unsaturated polymerizablesubstances include ethylene; styrenes such as styrene and methylstyrene; halogenated vinyl compounds such as vinyl chloride, vinylidenechloride and tetrafluoroethylene; acrylates; acrylamide; acrylonitrile;N-vinyl pyrrolidone; and substituted derivatives thereof. Examples ofacrylate monomers include butyl acrylate, 2-ethylhexyl acrylate, ethylacrylate, lauryl acrylate, hexadecyl acrylate, and methacrylatederivatives of these monomers. Examples of acrylamide monomers includeacrylamide, N,N-dimethyl acrylamide, N-ethyl acrylamide, N-isopropylacrylamide and hydroxymethyl acrylamide, and methacrylamide derivativesof these monomers.

In one example, the optional at least one other monomer 116 may includean α-(carboxylic acid)-alk-ω-ene molecule having the chemical formulaHO—C(═O)—(R⁵)—CH═CH₂, where R⁵ is an alkyl group having from 2 to 20carbon atoms. Examples of α-(carboxylic acid)-alk-ω-ene moleculesinclude but are not limited to 9-decenoic acid, 10-undecenoic acid and11-dodecenoic acid. An α-(carboxylic acid)-alk-ω-ene molecule may beformed by hydrolyzing an α-ester-alk-ω-ene molecule 114.

The reaction mixture 110 includes the first monomer 112, the secondmonomer 114, and optionally at least one other monomer 116. The reactionmixture may include only these monomers, or it may include one or moreother substances, such as a solvent, a buffer or a salt. Examples ofsolvents include but are not limited to protic solvents such as water,methanol, ethanol, isopropyl alcohol (IPA) and butanol; and aproticsolvents such as tetrahydrofuran (THF), dioxane, dimethyl formamide(DMF), toluene and xylene.

Forming 101 the reaction mixture 110 containing the first monomer 112,the second monomer 114, and optionally at least one other monomer 116may include combining the monomers with an addition polymerizationinitiator. Examples of addition polymerization initiators include freeradical polymerization initiators, cationic polymerization initiatorsand anionic polymerization initiators. A polymerization initiator is notrequired in the reaction mixture 110, however, as additionpolymerization may be initiated by heat or by electromagnetic radiationsuch as visible or ultraviolet light.

Preferably forming 101 the reaction mixture 110 includes combining themonomers with a free radical addition polymerization initiator.Selection of a particular free radical polymerization initiator maydepend on a number of factors including but not limited to thepolymerization temperature, the type of comonomers, and whether asolvent is present in the reaction mixture. Examples of free radicalpolymerization initiators include but are not limited to peroxides suchas hydrogen peroxide; alkyl peroxides such as di-t-butyl peroxide,di-t-amyl peroxide, dilauroyl peroxide and2,5-bis(t-butylperoxy)-2,5-dimethylhexane; acyl peroxides; arylperoxides such as benzoyl peroxide, dicumyl peroxide and t-butylperoxybenzoate; and hydroperoxides such as t-butyl hydroperoxide.Examples of free radical polymerization initiators include but are notlimited to azo compounds such as 2,2′-azobisisobutyronitrile (AIBN),2,2′-azobis(2-methylbutyronitrile),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(2-amidino-propane)-dihydrochloride, and2,2′-azobis(N,N′-dimethylene-isobutylamidine). Examples of free radicalpolymerization initiators include but are not limited to persulfatessuch as potassium persulfate and ammonium persulfate. The amount ofpolymerization initiator may range, for example, from about 0.01 to 5mol % based on the total moles of comonomers present.

Forming 102 a product mixture 120 containing a copolymer 122 havingconstitutional units formed from the monomers 112, 114 and optionally116 may include heating the reaction mixture. The reaction mixture maybe heated to a temperature of at least about 30° C., including but notlimited to a temperature from about 30° C. to about 250° C., from about40° C. to about 200° C., from about 50° C. to about 175° C., or fromabout 60° C. to about 160° C. The reaction mixture may be heated for atleast about 1 hour, including but not limited to from about 1 hour toabout 100 hours, from about 5 hours to about 50 hours, from about 10hours to about 30 hours, or from about 15 hours to about 25 hours.

Forming 102 a product mixture 120 containing a copolymer 122 havingconstitutional units formed from the monomers 112, 114 and optionally116 may include isolating the copolymer 122. Isolating the copolymer mayinclude removing volatile starting material and/or byproducts underreduced pressure and/or heat. Isolating the copolymer may includedissolving the copolymer in a solvent to form a solution, andprecipitating the copolymer by contacting the solution with anon-solvent for the copolymer. Isolating the copolymer may includedissolving the copolymer in a solvent to form a solution, and removinglow molecular weight species from the solution by dialysis against thesolvent.

The yield of the copolymer 122 may be at least about 50%. Preferably theyield of the copolymer 122 is at least about 25%, at least about 40%, atleast about 50%, at least about 60%, at least about 70%, at least about80%, at least about 90%, or at least about 95%.

FIG. 2 depicts chemical structures and a reaction scheme for an exampleof a method 200 of forming a copolymer, such as copolymer for alubricant composition. Method 200 includes forming a reaction mixture210 containing a first monomer 212 that is an alpha-olefin, a secondmonomer 214 that is an α-ester-alk-ω-ene molecule, and optionally atleast one other monomer, such as a α-(carboxylic acid)-alk-ω-enemolecule 216. Method 200 further includes forming a product mixture 220containing a copolymer 222 formed from the monomers 212, 214 andoptionally 216. In the alpha-olefin monomer 212 and in copolymer 222, x′may be an integer from 0 to 20. In the α-ester-alk-ω-ene monomer 214 andin copolymer 222, y′ may be an integer from 1 to 19. In the optionalα-(carboxylic acid)-alk-ω-ene monomer 216 and in copolymer 222, z′ maybe an integer from 1 to 19. In the copolymer 222, x+y+z=1, where x maybe from 0.01 to 0.99, y may be from 0.01 to 0.99, and z may be from 0 to0.98. For example, x may be from 0.5 to 0.9, y may be from 0.1 to 0.5,and z may be from 0 to 0.4. Preferably x is from 0.65 to 0.9, y is from0.1 to 0.35, and z is from 0 to 0.25. Preferably the ratio of x to y isat least 2:1, and preferably the ratio of x to (y+z) is at least 2:1. Inthe copolymer 222, n may be from 2 to 100, from 3 to 50, or from 4 to25.

In one example, the alpha-olefin monomer 212 is 1-octene (x′=5),1-decene (x′=7), 1-dodecene (x′=9) or the like, or combinations thereof;and the α-ester-alk-ω-ene monomer 214 is 9-DAME (y′=6). In anotherexample, the alpha-olefin monomer 212 is 1-octene (x′=5), 1-decene(x′=7), 1-dodecene (x′=9) or the like, or combinations thereof; theα-ester-alk-ω-ene monomer 214 is 9-DAME (y′=6) or the like, and theα-(carboxylic acid)-alk-ω-ene monomer 216 is 9-decenoic acid (z′=6) orthe like. The copolymer 222 formed from these three monomers (212, 214and 216) also may be formed by polymerizing only monomers 212 and 214,and then partially hydrolyzing the methyl ester groups of theconstitutional units formed from the α-ester-alk-ω-ene monomer 214.

Referring again to FIG. 1, the copolymer 122 optionally may be combined103 with at least one other material 130. In one example, the copolymer122 is used as a base oil that is then combined with one or morelubricant additives. Examples of additives for lubricant compositionsinclude but are not limited to detergents, antiwear agents,antioxidants, metal deactivators, extreme pressure (EP) additives,dispersants, viscosity index improvers, pour point depressants,corrosion protectors, friction coefficient modifiers, colorants,antifoam agents and demulsifiers. In another example, the copolymer 122is used as a lubricant additive that is combined with a base oil,optionally with one or more other lubricant additives. For example, alubricant composition may include from 50 to 100% of a base oil, andfrom 0 to 50% of one or more lubricant additives. The relative amountsof the base oil and optional additives may be varied according to theuse of the lubricant composition. Lubricant compositions may be used inapplications include but not limited to motor oils, transmission fluids,gear oils, industrial lubricating oils, metalworking oils, hydraulicfluids, drilling fluids, greases, compressor oils, cutting fluids andmilling fluids.

Method 100 may produce a lubricant composition from renewablefeedstocks, and may advantageously provide simpler and/or morecost-effective production, reduced variability, improved sourcing, andincreased biorenewability than conventional methods for producing alubricant composition from petrochemical feedstocks. In addition,lubricant compositions formed by method 100 may have useful combinationsof properties, including but not limited to low viscosity, highviscosity, viscosity that can be varied from low to high, oxidativestability, thermal stability, and hydrolytic stability.

A low-viscosity lubricant composition may include a copolymer havingconstitutional units formed from monomers including a first alpha-olefinand an α-ester-alk-ω-ene molecule, and may have a kinematic viscosity at100° C. of at most 20 cSt. The first alpha-olefin preferably has from 8to 10 carbon atoms, and preferably includes 1-decene. Theα-ester-alk-ω-ene molecule preferably includes at least one of9-decenoic acid methyl ester, 9-decenoic acid ethyl ester, 9-decenoicacid propyl ester, 10-undecenoic acid methyl ester, 10-undecenoic acidethyl ester, 10-undecenoic acid propyl ester, 11-dodecenoic acid methylester, 11-dodecenoic acid ethyl ester and 11-dodecenoic acid propylester, and preferably includes 9-DAME.

The copolymer of the low-viscosity lubricant composition further mayhave constitutional units formed from a second alpha-olefin. Preferably,if the copolymer includes constitutional units formed from a secondalpha-olefin, the second alpha-olefin has from 8 to 16 carbon atoms. Thecopolymer of the low-viscosity lubricant composition optionally may haveconstitutional units formed from at least one other unsaturated monomer.

Preferably the low-viscosity lubricant composition has a kinematicviscosity at 100° C. of from 5 to 20 cSt, from 10 to 20 cSt, from 15 to20 cSt, from 5 to 15 cSt or from 10 to 15 cSt. The low-viscositycomposition may further include at most 50 wt % of a lubricant additive.

Method 100 may provide a low-viscosity lubricant composition having akinematic viscosity at 100° C. of at most 20 cSt. For example, the firstmonomer 112 may be a first alpha-olefin having from 8 to 10 carbon atomssuch as 1-decene, and the second monomer 114 may be an α-ester-alk-ω-enemolecule such as 9-DAME. The reaction mixture 110 further may includedi-t-amyl peroxide as a polymerization initiator. The reaction mixture110 further may include a chain transfer agent such as a thiol compoundor a halide compound.

A high-viscosity lubricant composition may include a copolymer havingconstitutional units formed from monomers including a first alpha-olefinand an α-ester-alk-ω-ene molecule, and may have a kinematic viscosity at100° C. of at least 40 cSt. The first alpha-olefin preferably has from12 to 16 carbon atoms, and preferably includes 1-dodecene. Theα-ester-alk-ω-ene molecule preferably includes at least one of9-decenoic acid methyl ester, 9-decenoic acid ethyl ester, 9-decenoicacid propyl ester, 10-undecenoic acid methyl ester, 10-undecenoic acidethyl ester, 10-undecenoic acid propyl ester, 11-dodecenoic acid methylester, 11-dodecenoic acid ethyl ester and 11-dodecenoic acid propylester, and preferably includes 9-DAME.

The copolymer of the high-viscosity lubricant composition further mayhave constitutional units formed from a second alpha-olefin. Preferably,if the copolymer includes constitutional units formed from a secondalpha-olefin, the second alpha-olefin has from 8 to 16 carbon atoms. Thecopolymer of the high-viscosity lubricant composition optionally mayhave constitutional units formed from at least one other unsaturatedmonomer.

Preferably the high-viscosity lubricant composition has a kinematicviscosity at 100° C. of from 40 to 100 cSt, from 40 to 80 cSt, from 40to 60 cSt, from 50 to 100 cSt, or from 50 to 80 cSt. The high-viscositycomposition may further include at most 50 wt % of a lubricant additive.

Method 100 may provide a high-viscosity lubricant composition having akinematic viscosity at 100° C. of at least 40 cSt. For example, thefirst monomer 112 may be a first alpha-olefin having from 12 to 16carbon atoms such as 1-decene, and the second monomer 114 may be anα-ester-alk-ω-ene molecule such as 9-DAME. The reaction mixture 110further may include di-t-butyl peroxide as a polymerization initiator.The method 100 may further include subjecting the copolymer to a firststripping at a temperature of at least 200° C., under a vacuum of from0.5 to 1 torr, and then subjecting the copolymer to a second strippingat a temperature of at least 200° C., under a vacuum of from 0.1 to 1torr. The method 100 may further include forming a second reactionmixture including the copolymer and di-t-butyl peroxide, and forming asecond product mixture containing a second copolymer. This secondcopolymer preferably has constitutional units formed from the first andsecond monomers, and has a weight average molecular weight that is atleast twice that of the original copolymer.

A variable-viscosity lubricant composition may include a copolymerhaving constitutional units formed from monomers including analpha-olefin, an α-ester-alk-ω-ene molecule and an α-(carboxylicacid)-alk-ω-ene molecule, and may have a kinematic viscosity at 100° C.that varies from 15 to 35 cSt as the ratio of the α-ester-alk-ω-enemolecule to the α-(carboxylic acid)-alk-ω-ene molecule in the monomersvaries from 99.9:0.1 to 0.1:99.9. For example, the alpha-olefin monomermay have from 8 to 16 carbon atoms, and preferably includes at least oneof 1-octene, 1-decene and 1-dodecene. The α-ester-alk-ω-ene moleculepreferably includes at least one of 9-decenoic acid methyl ester,9-decenoic acid ethyl ester, 9-decenoic acid propyl ester, 10-undecenoicacid methyl ester, 10-undecenoic acid ethyl ester, 10-undecenoic acidpropyl ester, 11-dodecenoic acid methyl ester, 11-dodecenoic acid ethylester and 11-dodecenoic acid propyl ester, and preferably includes9-DAME. The α-(carboxylic acid)-alk-ω-ene molecule preferably includesat least one of 9-decenoic acid, 10-undecenoic acid and 11-dodecenoicacid.

The copolymer of the variable-viscosity lubricant composition optionallymay have constitutional units formed from at least one other unsaturatedmonomer. The composition may further include at most 50 wt % of alubricant additive.

Method 100 may provide a variable-viscosity lubricant composition havinga kinematic viscosity at 100° C. that varies from 15 to 35 cSt as theratio of the α-ester-alk-ω-ene molecule to the α-(carboxylicacid)-alk-ω-ene molecule in the monomers varies from 99.9:0.1 to0.1:99.9. For example, the first monomer 112 may be an alpha-olefinhaving from 8 to 16 carbon atoms, the second monomer 114 may be anα-ester-alk-ω-ene molecule such as 9-DAME, and the at least one othermonomer 116 may be an α-(carboxylic acid)-alk-ω-ene molecule such as9-decenoic acid.

The following examples are provided to illustrate one or more preferredembodiments of the invention. Numerous variations can be made to thefollowing examples that lie within the scope of the invention.

EXAMPLES

Materials & Methods

Percent incorporation of comonomers was estimated using proton nuclearmagnetic resonance spectrometry (¹H-NMR). Residual monomer wasquantified with gas chromatography (GC), using a DB-5HT capillary column(J&W Scientific) and a flame ionization detector. The GC measurementsalso provided qualitative analysis of residual dimer, trimer andtetramer. Residual monomer, as well as reaction by-products, wereseparated and quantified with high performance liquid chromatography(HPLC), using an Agilent Zorbax Eclipse Plus C18 column and either arefractive index detector or a UV-visible detector.

Molecular weights of polymers were measured using gel permeationchromatography (GPC), using tetrahydrofuran (THF) as the mobile phase.The columns used in the GPC analysis were a guard column (VARIAN PLgel 5μm guard column), a first separation column (200-400,000 daltons; VARIANPLgel 5 μm MIXED-D), and a second separation column (<30,000 daltons;VARIAN PLgel 3 μm MIXED-E).

Kinematic viscosity was measured at 40° C. and/or at 100° C. usingtemperature controlled oil baths. As Brookfield dynamic viscosity scaledwith the kinematic viscosity for some of the copolymers, kineticviscosities for some samples were calculated from Brookfield dynamicviscosity measurements. Kinematic viscosity (KV) is reported in units ofcentistokes (cSt).

Example 1 Copolymerizations of 1-decene and 9-DAME

Copolymers were formed by reacting an alpha-olefin monomer (1-decene)and an α-ester-alk-ω-ene monomer (9-DAME). In an initial polymerizationreaction, a reaction mixture was formed containing a 10:1 molar ratio of1-decene to 9-DAME. To this mixture was added di-t-butyl peroxide ordi-t-amyl peroxide as the polymerization initiator. The peroxide wasadded to the reaction mixture in ten equal portions. The reactionmixture was maintained at room temperature until the first peroxideaddition was complete, after which the reaction mixture was heated to150° C. In some instances, the monomers were sparged before thereaction, the reaction mixture was heated prior to adding the initiator,and/or a static inert gas atmosphere was established using an inlet onthe top of the condenser rather than an inlet and outlet, which wouldallow flow of the inert gas through the reaction. Peroxide decompositionproducts were generated throughout the reaction, producing volatilealkanes, ketones and alcohols. As these decomposition products couldcool the reaction temperature if left in the reaction mixture, aDean-Stark trap was used to remove and collect moderately volatileproducts. The trap was separated from the reaction vessel by a Vigreuxcolumn, to inhibit carryover of monomer and/or peroxide into the trap,which would reduce the yield.

In one example, 250 grams (g) of 1-decene (Aldrich; 1.78 mol), 33 g of9-DAME (0.178 mol) and 16.25 milliliters (mL) of di-t-butyl peroxide(density of 0.8 grams per milliliter (g/mL); 13 g; 0.089 mol) werecombined to form a reaction mixture in a 1-liter, 3-necked round-bottomflask equipped with a magnetic stirrer, a gas inlet, a gas outlet, athermometer, a Dean-Stark trap and a condenser. A low flow of nitrogengas was established in the flask, and the reaction mixture was heated to150° C. Once the mixture was at 150° C., another 16.25 mL of di-t-butylperoxide (13 g; 0.089 mol) was added to the reaction mixture. The totalmolar amount of di-t-butyl peroxide in the reaction was equal to themolar amount of 9-DAME, which corresponded to 8.3 mole percent (mol %)of the total reaction (moles peroxide/(moles peroxide+molesmonomers)=0.0833). The reaction mixture was stirred at 150° C. for 5-10hours, and liquid in the Dean-Stark trap was removed periodically. Theresulting clear product was allowed to cool to room temperature underthe nitrogen flow, and was transferred to a short path distillationapparatus and then vacuum-stripped to remove unreacted monomer (1-deceneand/or 9-DAME). The product yield left in the pot of the distillationapparatus was about 66%.

In another example, 112.86 g of 1-decene (Aldrich; 0.80 mol) and 14.83 gof 9-DAME (0.08 mol) were combined to form a monomer mixture in a 250mL, 3-necked round-bottom flask equipped with a magnetic stirrer, a gasinlet, a gas outlet, a thermocouple-controlled heating mantle, aDean-Stark trap and a condenser. The monomer mixture was sparged withnitrogen for at least 1 hour, and then heated to 150° C. under a lowflow of nitrogen gas. Once the mixture was at 150° C., 1/10^(th) of thedi-t-amyl peroxide initiator was added by syringe to form a reactionmixture. As the total amount of di-t-amyl peroxide initiator used in thereaction was 24.54 g (30 mL; density of 0.82 g/mL; 0.14 mol), eachaddition of 1/10^(th) of the initiator was 3.0 mL. Aliquots of 3.0 mL ofdi-t-amyl peroxide were added to the reaction mixture every 30 minutes,resulting in a total addition time for the initiator of 4.5 hours. Thereaction mixture typically began to reflux after 3 or 4 additions of theinitiator, and liquid typically began to collect in the trap after 6additions of the initiator. Once all the initiator was added, thereaction mixture was stirred at 150° C. for 4 hours, and then theproduct mixture was allowed to cool to room temperature. The flask wasequipped with a short path distillation apparatus for stripping, and theproduct mixture was slowly heated to 200° C. under vacuum, usingthermocouple-controlled heating. Stripping at 200-205° C. at a pressurebelow 2 torr removed the residual monomer, to a level of less than 0.25%in the product, resulting in a product left in the flask that wascolorless to pale yellow, and slightly hazy. This product was filteredwhile warm (˜70-100° C.) using a medium coarseness paper filter or acoarse fritted filter. The yield of pale yellow product was at least85%. This example was scaled-up by carrying out the reaction in a 5-Lflask, using 1,504.85 g 1-decene (10.73 mol), 197.70 g 9-DAME (1.07 mol)and 400 mL of di-t-amyl peroxide (1.88 mol). This example was furtherscaled-up by carrying out the reaction in a 12-L flask, using 3,762.12 g1-decene (26.82 mol), 494.25 g 9-DAME (2.68 mol) and 1 L of di-t-amylperoxide (4.69 mol).

Example 2 Copolymerization of 1-decene and 9-DAME—Effects of PeroxideType, Temperature and Initiator Addition

A designed experiment (DOE) was conducted to study the effect of thevariables of peroxide type, mode of addition of the peroxide, andtemperature on the copolymerization of a 10:1 molar ratio of 1-deceneand 9-DAME. Five different peroxides were used—di-t-butyl peroxide,di-t-amyl peroxide, dicumyl peroxide, dibenzoyl peroxide, and dilauroylperoxide. The amount of initiator in each copolymerization was 8.3 mol %peroxide, calculated as moles peroxide/(moles peroxide+moles monomers).The three reaction temperatures corresponded to the 30, 60 and 120minute half-lives of each peroxide. The three different modes ofaddition were defined as: a) Mode 1—10% of the peroxide added at 30minute intervals, with a total addition time of 4.5 hours; b) Mode 2—10%of the peroxide added at 60 minute intervals, with a total addition timeof 9 hours; c) Mode 3—30% of the peroxide added initially, followed by10% at 30 minute intervals, with a total addition time of 3.5 hours. Allreactions were conducted in a 250 ml flask.

Table 1 lists the reaction variables, reaction yield, kinematicviscosity (KV) at 100° C. and color of the products. JMP software wasused to analyze the data. All of the copolymers had KV at 100° C. below21 cSt.

TABLE 1 Reaction variables and results for copolymerizations of 1-deceneand 9-DAME Variables Initiator Initiator Reaction Reaction Resultsaddition half-life temperature time KV at 100 Initiator mode (min) (°C.) (min) Yield (%) ° C. (cSt) Color di-t-amyl Mode 1 30 149.5 8.5 59.415.56 pale peroxide Mode 1 120 137.0 20.5 63.9 13.32 pale Mode 2 60143.1 17.0 68.4 12.71 pale Mode 3 30 149.5 7.5 61.4 13.01 paledi-t-butyl Mode 1 60 149.1 12.5 52.7 17.35 pale peroxide Mode 1 120143.0 20.5 56.8 15.53 pale Mode 2 60 149.1 17.0 47.9 20.49 pale Mode 330 155.4 7.5 46.6 20.81 pale benzoyl Mode 3 60 91.7 11.5 42.8 10.89 darkperoxide yellow dibenzoyl Mode 1 30 97.8 8.5 41.4 13.08 dark peroxideyellow Mode 2 120 85.9 25.0 41.5 12.61 dark yellow dicumyl Mode 1 60137.0 12.5 46.7 15.55 light peroxide yellow Mode 2 30 143.3 13.0 54.016.22 light yellow Mode 3 120 130.8 19.5 52.6 13.26 light yellowdilauroyl Mode 1 60 81.1 12.5 27.2 9.24 pale peroxide Mode 2 30 86.813.0 28.1 9.45 pale Mode 3 120 75.7 19.5 29.2 7.61 pale

The initiator di-t-amyl peroxide provided the highest yield of copolymer(55-70%), while providing kinematic viscosities between 12 and 16 cSt.The initiator di-t-butyl peroxide provided copolymer yields of from45-57%, and kinematic viscosities between 15 and 30 cSt. The initiatordicumyl peroxide provided copolymer yields of from 45-55%, and kinematicviscosities between 10 and 20 cSt. The initiator dibenzoyl peroxideprovided copolymer yields of from 40-45%, and kinematic viscositiesbetween 7 and 15 cSt. The initiator dilauroyl peroxide providedcopolymer yields of from 25-30%, and kinematic viscosities between 5 and10 cSt.

The effect of water on the copolymerization of 1-decene and 9-DAME wasstudied by using a hydroperoxide initiator, and by using di-t-butylperoxide initiator alone or in combination with water. Thepolymerization reactions were performed as described above, withreaction mixtures containing a 10:1 molar ratio of 1-decene to 9-DAME,and a reaction temperature of 155.4° C. The initiator was either t-butylhydroperoxide solution (70 wt % in water), di-t-butyl peroxide mixedwith water, or neat di-t-butyl peroxide. The amount of initiator in eachcopolymerization was 13.7 mol % peroxide, calculated as molesperoxide/(moles peroxide+moles monomers), and assuming a peroxidecontent of 70 wt % in the t-butyl hydroperoxide solution. Table 2 liststhe type of initiator, reaction yield, and kinematic viscosity (KV) at100° C. for the copolymerization reactions. The addition of water intothe reaction mixture appeared to reduce both the yield and the kinematicviscosity of the copolymer.

TABLE 2 Effect of water on copolymerizations of 1-decene and 9-DAMEYield KV at 100° C. Initiator (%) (cSt) Color t-butyl hydroperoxide,11.5 8.44 dark yellow 70 wt % in water di-t-butyl peroxide + 39.5 15.19pale, slightly cloudy water di-t-butyl peroxide 72.2 29.31 pale,transparent

The effect of combining peroxide initiators in the copolymerization of1-decene and 9-DAME was studied by comparing the results ofcopolymerizations carried out with di-t-butyl peroxide initiator, withdi-t-amyl peroxide initiator, or with a 1:1 combination of di-t-butylperoxide and di-t-amyl peroxide. The copolymerization reactions wereperformed as described above, with reaction mixtures containing a 10:1molar ratio of 1-decene to 9-DAME, and a total initiator loading of 13.7mol % peroxide. The reaction temperatures were selected based on the 30minute halflives of each initiator, with the reaction temperature of thecopolymerization with 1:1 di-t-butyl peroxide and di-t-amyl peroxidecalculated based on an average of the two initiator halflives. Table 3lists the type and amounts of each initiator, reaction temperature,reaction yield, and kinematic viscosity (KV) at 100° C. for thecopolymerization reactions. The combination initiator provided thehigher yield associated with di-t-amyl peroxide, and provided thekinematic viscosity associated with di-t-butyl peroxide.

TABLE 3 Effect of combining initiators on copolymerizations of 1-deceneand 9-DAME Reaction Temp Yield KV at 100° C. Initiator (° C.) (%) (cSt)di-t-amyl peroxide 149.5 93.2 19.15 89.6 19.40 1:1 di-t-butyl peroxide +152 92.4 32.56 di-t-amyl peroxide di-t-butyl peroxide 155.4 80.5 32.82

Example 3 Copolymerization of 1-decene and 9-DAME—Effects of PeroxideLoading

Copolymers were formed by reacting 1-decene as the alpha-olefin monomerand 9-DAME as the α-ester-alk-ω-ene monomer, with different amounts ofeither di-t-amyl peroxide or di-t-butyl peroxide as the initiator. Thecopolymerization reactions were performed as described in Example 1,with reaction mixtures containing a 10:1 molar ratio of 1-decene to9-DAME, a reaction temperature of 149.5° C. for copolymerizations usingdi-t-amyl peroxide, and a reaction temperature of 155° C. forcopolymerizations using di-t-butyl peroxide. Table 4 lists the amount ofinitiator, reaction yield, and kinematic viscosity (KV) at 100° C. forthe copolymerization reactions. Both the reaction yields and thekinematic viscosities increased as the initiator loading increased. Inaddition, the type of initiator affected the viscosity of thecopolymers. The di-t-amyl peroxide was more effective at providing alow-viscosity copolymer than was the di-t-butyl peroxide initiator.

TABLE 4 Copolymerizations of 1-decene and 9- DAME with differentperoxide initiators Initiator Reaction temp Yield KV at 100° C.Initiator (mol %) (° C.) (%) (cSt) di-t-amyl peroxide 8.4 149.5 59.915.20 di-t-butyl peroxide 8.3 155 49.9 18.54 di-t-amyl peroxide 13.8149.5 89.1 15.02 di-t-butyl peroxide 13.7 155 72.2 29.31

Copolymers were formed by reacting 1-decene and 9-DAME, with differentamounts of di-t-amyl peroxide initiator. The copolymerization reactionswere performed as described in Example 1, with reaction mixturescontaining a 10:1 molar ratio of 1-decene to 9-DAME, a “Mode 1” additionprofile for the initiator, and a reaction temperature of 149.5° C. Theamount of di-t-amyl peroxide initiator was varied from 2.2 mol % to 15.5mol %. The kinematic viscosities, molecular weights and elementalcomposition of the resulting copolymers were measured.

Table 5 lists the amount of initiator, reaction yield, kinematicviscosity (KV) at 100° C., and molecular weights of the copolymers asmeasured by GPC. The polydispersity index (PDI) was calculated as weightaverage molecular weight (M_(w)) divided by number average molecularweight (M_(n)). In addition, the copolymers were analyzed by elementalanalysis, which indicated that the oxygen contents in each of thecopolymers were higher than the theoretical values. The oxygen contentsdid not appear to correlate with the loading of the initiator.

TABLE 5 Reaction variables and results for copolymerizations of 1-deceneand 9-DAME Initiator Yield KV at 100° C. (mol %) (%) (cSt) M_(n) M_(w)PDI 2.2 10.0 10.92 606 847 1.33 4.4 27.6 13.82 661 826 1.40 6.4 49.211.53 612 801 1.31 8.4 59.9 15.20 656 846 1.29 10.2 71.1 15.91 759 10511.38 12.1 78.8 15.47 702 954 1.36 13.8 89.1 15.02 682 917 1.34 15.5 92.618.97 744 1187 1.60

FIG. 3 is a graph of copolymer molecular weights and of polydispersitiesas a function of di-t-amyl peroxide initiator loading, where the datapoints are from Table 5.

Increasing the amount of di-t-amyl peroxide initiator above 8.4 mol %provided higher molecular weight copolymers.

FIG. 4 is a graph of reaction yield and of copolymer viscosity as afunction of di-t-amyl peroxide initiator loading, where the data pointsare from Table 5. The reaction yield increased as the initiator loadingincreased. Each of the copolymers had KV at 100° C. below 19 cSt. Arelatively narrow range of viscosities, from 15.02 to 15.91 cSt, wasmeasured for copolymers produced using from 8.4 to 13.8 mol % initiator.

Example 4 Copolymerization of 9-DAME with alpha-olefins other than1-decene

Copolymers were formed by reacting one, two or three differentalpha-olefin monomers (1-octene, 1-decene and/or 1-dodecene) and anα-ester-alk-ω-ene monomer (9-DAME), with di-t-amyl peroxide initiator.The molar ratio of alpha-olefin(s) to 9-DAME in each copolymerizationwas 10:1, and the initiator was present at a loading of 13.7 mol %.Although the copolymerization reactions were performed with refluxing,the reaction temperatures depended on the identity of the comonomers.Table 6 lists the type and amount of monomers, the boiling point of eachmonomer, the reaction yield, and the kinematic viscosity (KV) at 100° C.for the copolymerization reactions.

TABLE 6 Copolymerizations of different alpha-olefins and 9-DAME Monomer(equivalents) 1-Octene (bp 1-Decene (bp 1-Dodecene 9-DAME (bp Yield KVat 100° C. 122° C.) 171° C.) (bp 213° C.) 120° C.*) (%) (cSt) 10  — — 161.9** 12.47 — 10  — 1 93.9 19.44 — — 10  1 95.5 22.44 5 5 — 1 82.422.81 — 5 5 1 94.9 20.44 5 — 5 1 93.4 20.14   3.33   3.33   3.33 1 91.922.31 *Boiling point at 1 torr pressure. **The reaction temperature waslimited to 125-130° C.

The low boiling point of 1-octene appeared to preclude the 10:11-octene/9-DAME copolymerization reaction from reaching the typicalreaction temperature of 149.5° C. This lower reaction temperatureappeared to provide a lower yield and a lower kinematic viscosity forthe resulting copolymer. Copolymerizations in which 1-octene wascombined with another alpha-olefin were able to maintain reactiontemperatures of 149.5° C., and the yields and kinematic viscosities ofthe resulting copolymers were similar to that of the 10:11-decene/9-DAME copolymer. Accordingly, 1-octene may be a usefulcomonomer when combined with other alpha-olefins having higher boilingpoints.

Copolymers were formed by reacting an α-ester-alk-ω-ene monomer (9-DAME)and either 1-decene or 1-dodecene as the alpha-olefin monomer. The molarratio of alpha-olefin(s) to 9-DAME was varied, with ratios of 10:1, 3:1or 1:1. The peroxide initiator was either di-t-amyl peroxide ordi-t-butyl peroxide, and the loading of the initiator was either 13.7mol % or about 8.4 mol %. Table 7 lists the monomers, monomer ratios,type of initiator, initiator loading, reaction yield, and kinematicviscosity (KV) at 100° C. for the copolymerization reactions. Inaddition, the differences in the yield and in the kinematic viscositybetween comparable copolymerization reactions that differed only in theidentity of the alpha-olefin are listed in the table. The effect ofsubstituting 1-dodecene for 1-decene in the copolymerizations dependedon the peroxide used, the amount of peroxide, and on the molar ratio ofthe alpha-olefin to 9-DAME.

TABLE 7 Copolymerizations of 9-DAME with either 1-decene or 1-dodeceneAlpha-olefin Initiator Yield Yield KV at 100° C. KV (molar ratio*) (mol%) (%) difference (cSt) difference 1-decene (10:1) di-t-amyl peroxide93.9 1.7% 19.44 14.3% 1-dodecene (10:1) (13.7) 95.5 22.44 1-decene(10:1) di-t-butyl peroxide 60.2 18.7% 21.07 10.4% 1-dodecene (10:1)(8.3) 72.7 23.19 1-decene (10:1) di-t-butyl peroxide 80.5 6.4% 32.826.8% 1-dodecene (10:1) (13.7) 85.8 35.14 1-decene (3:1) di-t-butylperoxide 68.9 5.5% 17.80 18.9% 1-dodecene (3:1) (8.5) 72.8 23.391-decene (3:1) di-t-butyl peroxide 87.2 3.8% 31.48 21.2% 1-dodecene(3:1) (13.7) 90.6 38.93 1-decene (1:1) di-t-amyl peroxide 95.0 0.6%28.81 1.3% 1-dodecene (1:1) (13.7) 95.6 29.18 *Of alpha-olefin to9-DAME.

Example 5 Copolymerization of 1-decene and 9-DAME—Effects of 9-DAMELoading

Copolymers were formed by reacting an alpha-olefin monomer (1-decene)and an α-ester-alk-ω-ene monomer (9-DAME), where the mole percent of9-DAME in the monomer mixture was varied from 0 mol % to 9.1 mol %. Theinitiator was di-t-amyl peroxide, which was present in the reactionmixtures at a loading of 8.4 mol %. The reactions were held at 149.5° C.for 4 hours after the last addition of the initiator, and the productswere isolated as described above. Table 8 lists the amount of eachmonomer, the reaction yield, and the kinematic viscosity (KV) at 100° C.for the copolymerization reactions.

TABLE 8 Copolymerizations of 1-decene with different amounts of 9-DAME1-decene (mol % of 9-DAME monomers) (mol % of monomers) Yield (%) KV at100° C. (cSt) 100 0 59.9 15.44 99 1 57.9 15.48 97 3 57.3 15.44 95 5 57.814.60 92.5 7.5 61.0 14.35 90.9 9.1 59.9 15.20

The yield and kinematic viscosity at 100° C. were not substantiallyaffected by the variation of the amount of 9-DAME from 0 to 9.1 mol %.Accordingly, at these monomer incorporation levels, the kinematicviscosity was not substantially affected by differences in the polarityof the copolymers. In addition, the percentage of comonomer in thecopolymer that was derived from 9-DAME, as determined by

¹H-NMR, was consistent with the percentage of 9-DAME in the monomermixture. Accordingly, 1-decene and 9-DAME had substantially equivalentreactivity in these copolymerization reactions.

Example 6 Copolymerization of 1-decene, 9-DAME and 9-DA

Copolymers were formed by reacting 1-decene, an α-ester-alk-ω-enemonomer (9-DAME) and/or an α-(carboxylic acid)-alk-ω-ene monomer(9-decenoic acid; 9-DA), with di-t-amyl peroxide initiator. The molarratio of alpha-olefin to the 9-DAME and/or 9-DA in each copolymerizationwas 10:1. Table 9 lists the type and amount of monomers, the reactionyield, and the kinematic viscosity (KV) at 100° C. for thecopolymerization reactions.

TABLE 9 Copolymerizations of 1-decene with 9-DAME and/or 9-DA Monomer(equivalents) 1-decene 9-DAME 9-DA Yield (%) KV at 100° C. (cSt) 10 1 088.8 15.53 10 0.5 0.5 85.7 28.1 10 0 1 89.4 33.70

These three copolymers can provide information regarding the potentialeffects of hydrolysis on copolymers of alpha-olefins andα-ester-alk-ω-ene monomers. Hydrolysis of ester groups may occur due toinadvertent introduction of water during the copolymerization orstripping processes, and also may occur during use of a lubricantcomposition containing the copolymer. One effect of the presence ofcarboxylic acid groups in the copolymers was an increase in viscosity.

Example 7 Copolymerization of 1-dodecene and 9-DAME—Effects of PeroxideType and Loading

Copolymerizations were performed with 1-dodecene as the alpha-olefinmonomer instead of 1-decene. The α-ester-alk-ω-ene monomer was 9-DAME,and copolymers were formed by reacting 1-dodecene and 9-DAME withdifferent amounts of di-t-butyl peroxide initiator. The polymerizationreactions were performed as described in Example 1, with reactionmixtures containing a 10:1 molar ratio of 1-dodecene to 9-DAME, and areaction temperature of 155° C. The amount of di-t-butyl peroxideinitiator was varied from 4.0 mol % to 13.7 mol %. Table 10 lists theamount of initiator, reaction yield, and kinematic viscosity (KV) at100° C. for the copolymerization reactions.

TABLE 10 Copolymerizations of 1-dodecene and 9-DAME Initiator (mol %)Yield (%) KV at 100° C. (cSt) 4.0 44.2 15.61 6.0 58.2 18.25 8.3 73.222.51 8.3 72.1 21.75 13.7 85.8 32.17

Copolymers were formed by reacting 1-dodecene and 9-DAME in a molarratio of 10:1, using different peroxide initiators. In addition todi-t-butyl peroxide and di-t-amyl peroxide,2,5-bis(t-butylperoxy)-2,5-dimethylhexane and t-butyl peroxybenzoatewere used as polymerization initiators. The2,5-bis(t-butylperoxy)-2,5-dimethylhexane initiator could generate twoequivalents of radicals per molecule, theoretically requiring half asmuch initiator in a copolymerization. Table 11 lists the type and amountof initiator, reaction yield, and kinematic viscosity (KV) at 100° C.for the copolymerization reactions.

FIG. 5 is a graph of reaction yield and of copolymer viscosity as afunction of initiator loading, where the data points are from Table 11.Both the reaction yields and the kinematic viscosities increased as theinitiator loading increased. In addition, the type of initiator affectedthe viscosity of the copolymers. As shown in FIG. 5, the copolymersformed using di-t-butyl peroxide had a steeper rate of increase inkinematic viscosity (KV) with increasing initiator loading than did thecopolymers formed using di-t-amyl peroxide. The kinematic viscosity ofthe copolymers formed using di-t-amyl peroxide were at most 26.85 cSt,even at 16 mol % initiator loading. Accordingly, di-t-butyl peroxide wasmore effective at providing a high-viscosity copolymer, whereasdi-t-amyl peroxide more effective at providing a low-viscositycopolymer.

TABLE 11 Copolymerizations of 1-dodecene and 9-DAME KV at InitiatorInitiator mol % Yield (%) 100° C. (cST) di-t-butyl peroxide 2 24.5 14.533 36.1 14.53 4 44.2 15.61 6 58.2 18.25   8.3 73.2 22.51   8.3 72.1 21.7512  86.0 30.82  13.7 85.8 32.17 14  91.2 39.22 16  94.3 51.102,5-bis(t-butylperoxy)-2,5-  2* 37.7 15.68 dimethylhexane  2* 40.0 15.35 4* 64.2 17.73 t-butyl peroxybenzoate 8 64.0 19.52 di-t-amyl peroxide 449.0 13.79 8 78.3 15.81 12  93.3 19.20 14  96.7 22.44 16  97.9 26.85*Equivalents of initiator = 2 × mol %; i.e. 4, 4 and 8 equivalent %,respectively.

Copolymerizations using the 2,5-bis(t-butylperoxy)-2,5-dimethylhexaneinitiator had a slightly lower yield than those using di-t-butylperoxide, but both types of copolymerizations produced copolymers havingsimilar kinematic viscosities at 100° C. The t-butyl peroxybenzoateinitiator also had a lower yield, and the resulting copolymers had alight yellow color. In addition, isolating the copolymers formed usingt-butyl peroxybenzoate was more difficult than in othercopolymerizations, as the benzoic acid byproduct of the reaction cansolidify in a distillation condenser.

Example 8 Copolymerization of 1-dodecene and 9-DAME—Effects of ComonomerRatios

Copolymers were formed by reacting by reacting an alpha-olefin monomer(1-dodecene) and an α-ester-alk-ω-ene monomer (9-DAME) in varyingratios. Copolymerization reaction mixtures were formed by combining1-dodecene and 9-DAME in molar percentages of from 95 to 25 mol %1-dodecene, and from 5 to 75 mol % 9-DAME. In addition, a polymerizationreaction mixture was formed by adding di-t-butyl peroxide to 9-DAMEwithout any alpha-olefin comonomer. The amount of di-t-butyl peroxidepolymerization initiator in each reaction was 8.3-8.4 mol %, and thereaction temperatures were from 150-155° C. Table 12 lists the amount ofeach monomer, the amount of initiator, reaction yield, and kinematicviscosity (KV) at 100° C. for the polymerization and copolymerizationreactions.

TABLE 12 Copolymerizations of 1-dodecene and 9-DAME, and polymerizationof 9-DAME 1-Dodecene 9-DAME di-t-butyl (monomer (monomer peroxide KV at100° C. mol %) mol %) (mol %) Yield (%) (cSt) 95 5 8.4 70.0 22.30 90.99.1 8.4 69.9 21.73 8.3 73.2 22.51 8.3 72.1 21.75 85 15 8.4 69.0 20.91 7525 8.4 70.5 20.77 8.3 72.8 21.38 65 35 8.4 69.7 19.99 50 50 8.4 70.720.34 25 75 8.4 73.0 21.49 0 100 8.4 74.1 23.17

FIG. 6 is a graph of reaction yield and of copolymer viscosity as afunction of 9-DAME monomer percentage for reactions with 8.4 mol %di-t-butyl peroxide, where the data points are from Table 12. Thereaction yields were similar between the different reactions. Thekinematic viscosity appeared to be lowest for copolymers formed frommonomer mixtures containing from 25 to 50 mol % 9-DAME, with a minimumkinematic viscosity observed for the copolymer formed with 35 mol %9-DAME. The viscosity index appeared to decrease with increasing 9-DAMElevels. Table 13 lists the kinematic viscosity (KV) at 100° C., thekinematic viscosity (KV) at 40° C., and the viscosity index (VI) for thepolymerization and copolymerization reactions corresponding to Table 12entries for 95% 1-dodecene, 75% 1-dodecene (using 8.4 mol % peroxide),and 50%, 25% and 0% 1-dodecene, respectively.

TABLE 13 Kinematic viscosities and viscosity indices of copolymersformed from 1-dodecene and 9-DAME, and of a polymer formed from 9-DAME1-dodecene/9- DAME ratio KV at 100° C. (cSt) KV at 40° C. (cSt) VI 19:1 22.30 157.70 169 3:1 20.77 146.90 165 1:1 20.34 141.46 167 1:3 21.49159.49 160 —* 23.17 177.85 158 *Polymerization of 9-DAME without1-dodecene

Copolymers were formed by reacting 9-DAME and olefin compositionscontaining 1-dodecene in molar ratios of 1-dodecene to 9-DAME ofapproximately 10:1 and of 1:1. The olefin compositions includeddifferent combinations of isomers. Feedstock A included 95.4% 1-dodecene(n-isomer), 3.8% 2-methly-1-undecene (vinylidene isomer), and 0.15%2-dodecene and other internal olefins. Feedstock B included a loweramount of 1-dodecene, containing 91.1% 1-dodecene, 7.2%2-methly-1-undecene, and 1.7% 2-dodecene and other internal olefins. Theamount of di-t-butyl peroxide initiator in each copolymerizationreaction was 8.4 mol %, and the reaction temperature was 150° C. Table14 lists the olefin feedstock, the approximate molar ratio of thecomonomers, reaction yield, and kinematic viscosity (KV) at 100° C. forthe copolymerization reactions. The copolymers formed using an olefinfeedstock having a higher level of non-alpha-olefin isomers had loweryields and lower kinematic viscosities at 100° C.

TABLE 14 Copolymerizations of 9-DAME with 1-dodecene from differentolefin feedstocks ~1-dodecene/9- Feedstock DAME ratio Yield (%) KV at100° C. (cSt) A 10:1 70.5 21.90 B 10:1 64.5 18.17 A  3:1 70.5 20.77 B 3:1 67.5 18.35

Example 9 Copolymerization of 1-dodecene and 9-DAME with Chain TransferAgents

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer (9-DAME) in a molar ratio of 10:1,using 8.3 mol % di-t-butyl peroxide polymerization initiator, and addinga thiol compound as a chain transfer agent. Table 15 lists the type andamount of chain transfer agent (CTA), reaction temperature, reactionyield, kinematic viscosity (KV) at 100° C., and residual sulfur levelsfor the copolymerization reactions. The CTA mol % was calculated as themoles of chain transfer agent as a percentage of the total moles ofmonomer. The copolymers formed using 0.3 mol % t-nonyl thiol wereisolated using two stripping procedures, due to an undesirable odorafter the initial stripping.

TABLE 15 Copolymerizations of 1-dodecene and 9-DAME with thiol-basedchain transfer agents Chain Reaction transfer CTA temp KV at 100° C. ppmagent mol % (° C.) Yield (%) (cSt) Sulfur — 0 140 52.9 16.89 <10 stearylthiol 0.1 150 56.1 17.43 268 dodecyl thiol 0.3 140 47.2 12.91 1180 16064.9 15.69 847 t-nonyl thiol 0.1 150 60.3 17.31 197 0.3 140 35.6 12.031070 0.3 160 49.8 12.88 927

Both yield and kinematic viscosity decreased with the use of these chaintransfer agents. This viscosity was lower than what was previouslyobtained by lowering the amount of peroxide initiator or lowering thereaction temperature. Accordingly, the chain transfer agents appeared topromote chain transfer reactions in the copolymerizations, whilemaintaining desirably high levels of chain propagation and desirably lowlevels of chain termination. The copolymer molecular weights werereduced without lowering the overall monomer conversion.

Copolymers were formed by reacting 1-dodecene and 9-DAME in a molarratio of 10:1, using 8.3 mol % di-t-butyl peroxide polymerizationinitiator, and adding 0.3 mol % of different chain transfer agents. Theinitiator was added in 1/10 aliquots every 30 minutes, and the reactionmixtures were stirred at 150° C. for 4 hours after completion of theinitiator addition. Table 16 lists the type and amount of chain transferagent (CTA), reaction temperature, reaction yield, kinematic viscosity(KV) at 100° C., thermogravimetric (TGA) volatility, and residual sulfurlevels for the copolymerization reactions.

TABLE 16 Copolymerizations of 1-dodecene and 9-DAME with various chaintransfer agents Chain transfer CTA Yield KV at 100° C. TGA Sulfur agentmol % (%) (cSt) volatility (%) (ppm) — 0 70.55 21.90 5.2 <10 dodecylthiol 0.3 60.1 15.37 7.6 1000 octyl thiol 0.3 59.5 14.88 7.5 — t-nonylthiol 0.3 47.5 11.28 8.1 1180 BrCCl₃ 0.3 50.7 11.31 7.4 * octyl bromide0.3 66.4 19.09 6.1 — t-amyl bromide 0.3 50.5 12.53 7.6 — octyl alcohol0.3 70.5 21.70 5.2 — t-amyl alcohol 0.3 69.4 21.21 4.9 — cyclohexadiene0.3 69.7 21.26 5.5 — terpinolene 0.3 68.3 20.73 5.4 — γ-terpinene 0.369.4 20.78 5.5 — * 3490 ppm Cl; 725 ppm Br.

Within the R—X series, chain transfer effectiveness increased in theseries OH<Br<SH. Neither the primary nor tertiary alcohols showed chaintransfer activity in these copolymerizations. The tertiary alkyl bromideshowed greater activity than the primary alkyl bromide, and wascomparable to the activity of the tertiary thiol and of BrCCl₃ in thesecopolymerizations. One side effect of using the tertiary bromide or thebromotrichloromethane, however, was that the copolymer had a goldenyellow color.

Copolymers were formed by reacting 1-dodecene and 9-DAME in a molarratio of 10:1, using either di-t-butyl peroxide or di-t-amyl peroxide asthe polymerization initiator, and adding t-nonyl thiol as a chaintransfer agent at loadings of 0, 0.1, 0.15 or 0.30 mol %. Table 17 liststhe amount of t-nonyl thiol chain transfer agent (CTA), the type andamount of initiator, reaction temperature, reaction yield, and kinematicviscosity (KV) at 100° C. for the copolymerization reactions. Inaddition, the differences in the yield and in the kinematic viscositybetween comparable copolymerization reactions that differed only in thepresence of the chain transfer agent are listed in the table.

TABLE 17 Copolymerizations of 1-dodecene and 9-DAME with and withoutt-nonyl thiol chain transfer agent t-nonyl thiol CTA Temp Yield YieldKV, 100° C. KV (mol %) Initiator (mol %) (° C.) (%) difference (cSt)difference — di-t-butyl 150 70.5 21.9 0.10 peroxide (8.3) 150 60.3  14%* 17.31  4.59%* 0.30 155 47.5   23%* 11.28 10.62%* — di-t-butyl 15544.2 18.1% 15.61 7.83% 0.15 peroxide (4) 26.1 7.78 — di-t-butyl 150 78.318.1% 15.81 4.03% 0.15 peroxide (7.4) 60.2 11.78 — di-t-amyl 150 78.325.5% 15.81 6.45% 0.3 peroxide (8) 52.8 9.36 — di-t-amyl 150 49.0 18.8%13.79 3.92% 0.15 peroxide (4) 30.2 9.87 *Difference relative to not-nonyl thiol CTA.

For copolymerizations using 8.3 mol % di-t-butyl peroxide, lowering thethiol content did not reduce the viscosity to 10 cSt or less. Similarly,the control reaction with lower (4 mol %) peroxide but no thiol CTA didnot provide such a reduction in viscosity, although the copolymerizationyield was lower. The copolymerization using both a lower loading ofperoxide initiator and a lower loading of thiol CTA, however, provided aviscosity below 10 cSt. Substituting di-t-amyl peroxide as the initiatorprovided a higher yield and a lower copolymer viscosity than did thecorresponding copolymerization with di-t-butyl peroxide. FIG. 7 is agraph of copolymer viscosity as a function of reaction yield, where thedata points are from Table 17. The chain transfer agents highlighted inthe graph may provide lower viscosities than what had previously beenobtained for di-t-butyl peroxide initiated copolymerizations, while alsoproviding acceptable reaction yields.

Example 10 High Viscosity Lubricant Compositions ContainingCopolymerization Products of 1-dodecene and 9-DAME—Effect of Stripping

The viscosities of certain copolymers from Examples 4 and 8 wereincreased by one or more additional stripping procedures. The copolymersanalyzed had been formed by reacting 1-dodecene and 9-DAME in a molarratio of 3:1, using di-t-butyl peroxide as the polymerization initiator,at a reaction temperature of 155° C. One copolymer corresponded to thatlisted in Table 12 of Example 8 as the entry for 75% 1-dodecene using8.3 mol % peroxide. The other copolymer, corresponding to that listed inTable 7 of Example 4 as the 10^(th) entry, was formed using 13.7 mol %peroxide. Both copolymers had been stripped at 200° C. under a vacuum of1 torr after their copolymerization reactions. The copolymer formedusing the lower amount of 8.3 mol % peroxide was stripped at 250° C.under a vacuum of 0.25 torr, and then further stripped at 300° C. undera vacuum of 0.5 torr. The copolymer formed using the higher amount of13.7 mol % peroxide was stripped at 250° C. under a vacuum of 0.25 torr.Table 18 lists the amount of initiator, copolymer yield, kinematicviscosity (KV) at 100° C., kinematic viscosity (KV) at 40° C., andviscosity index.

TABLE 18 Change in yield, molecular weight and viscosity due tostripping of copolymers formed from a 3:1 molar ratio of 1-dodecene and9-DAME Initiator KV at 100° C. KV at 40° C. (mol %) Stripping Yield (%)M_(n) (PDI) (cSt) (cSt) VI 8.3 200° C.; 1 torr 72.8 1939 (1.65) 21.38152.56 165 250° C.; 0.25 torr 65.0* — 28.29 — — 300° C.; 0.50 torr —3687 (1.15) 26.52 215.57 157 13.7 200° C.; 1 torr 90.6 2522 (1.89) 38.93319.54 174 250° C.; 0.25 torr 84.1* 5946 (1.16) 48.01 436.1 170*Calculated based on weight loss from additional stripping.

Subjecting the copolymer formed using the lower amount of 8.3 mol %peroxide to stripping at 250° C. under 0.25 torr increased the kinematicviscosity at 100° C. from 21.38 to 28.29 cSt. This supplementalstripping also reduced the overall yield from 72.8% to 65.0%. Furthersubjecting this copolymer to stripping at 300° C. under 0.50 torr,however, reduced the kinematic viscosity at 100° C. to 26.52 cSt.Subjecting the copolymer formed using the higher amount of 13.7 mol %peroxide to stripping at 250° C. under 0.25 torr increased the kinematicviscosity at 100° C. from 38.93 to 48.01 cSt. This supplementalstripping also reduced the overall yield from 90.6% to 84.1%.

Stripping the copolymers removed lower molecular weight fractions, whichcontributed to lower kinematic viscosity in the original copolymers. Thekinematic viscosity at 100° C. was raised above 40 cSt with the highperoxide sample (13.7 mol % peroxide). Viscosity indices were somewhatreduced by the additional stripping, but remained relatively high.

Copolymers were formed by reacting 1-dodecene and 9-DAME in molar ratiosof 9:1 or 3:1, using 8 mol % di-t-butyl peroxide as the polymerizationinitiator. After stripping at 200° C. under a vacuum of 1 torr, theresulting copolymers were analyzed with regard to molecular weight,kinematic viscosity at 40° C. and 100° C., and viscosity index. Thestripping process and analysis were repeated three times, atsuccessively higher temperatures of 250° C., 260° C. and 275° C. Table19 lists the comonomer ratio, stripping temperature, copolymer yield,molecular weight (M_(n)) and polydispersity (PDI), kinematic viscosity(KV) at 100° C. and 40° C., and viscosity index.

TABLE 19 Change in yield, molecular weight and viscosity properties dueto stripping, of copolymers formed using 8 mol % di-t-butyl peroxide1-dodecene/ Stripping KV at 100° C. KV at 40° C. 9-DAME ratio Temp (°C.) Yield (%) M_(n) (PDI) (cSt) (cSt) VI 9:1 200 68.8 1696 (1.7) 20.78141.42 171 250 62.6* — 26.80 210.63 162 260 61.2* — 27.72 — — 275 59.3*2104 (1.5) 29.10 245.70 156 3:1 200 68.6 1650 (1.7) 19.72 137.33 165 25062.0* — 25.15 201.51 156 260 59.9* — 26.89 — — 275 58.4* 2047 (1.5)27.70 234.51 153 *Calculated based on weight loss from additionalstripping.

As the stripping temperature was raised, the molecular weight andkinematic viscosity of the copolymers increased, while thepolydispersity and viscosity index decreased. Analysis of thedistillates from each stripping process indicated that dimer and loweroligomers were removed from the copolymer, causing an increase in theaverage molecular weight of the copolymer and a narrowing of thepolydispersity.

Copolymers were formed by reacting 1-dodecene and 9-DAME in molar ratiosof 9:1, 3:1 or 1:1, using 11.3 mol % di-t-butyl peroxide as thepolymerization initiator. This loading of peroxide initiator wasselected as an intermediate loading between the 8-8.5 mol % peroxide and13.7 mol % peroxide loadings used in the copolymerizations describedabove. As the 8-8.5 mol % and 13.7 mol % peroxide copolymerizations hadprovided 100° C. kinematic viscosities below 40 cSt and above 40 cSt,respectively, an intermediate peroxide loading was expected to provide a100° C. kinematic viscosity closer to 40 cSt. The copolymerizationproducts were stripped at 200° C. under a vacuum of 1 torr, and thenanalyzed with regard to molecular weight, kinematic viscosity at 40° C.and 100° C., viscosity index and pour point. The stripping process andanalysis were repeated twice, at successively higher temperatures of250° C. and 275° C. Table 20 lists the comonomer ratio, strippingtemperature, copolymer yield, molecular weight (M_(n)) andpolydispersity (PDI), kinematic viscosity (KV) at 100° C. and 40° C.,and viscosity index.

TABLE 20 Change in yield, molecular weight and viscosity due tostripping of copolymers formed using 8 mol % di-t-butyl peroxide1-dodecene/ Stripping KV at 100° C. KV at 40° C. 9-DAME ratio Temp (°C.) Yield (%) M_(n) (PDI) (cSt) (cSt) VI 9:1 200 82.2 1834 (1.79) 27.68217.61 164 250 76.5* 2127 (1.61) 32.42 297.71 157 275 73.9* 2224 (1.56)36.61 336.52 156 3:1 200 82.3 1800 (1.79) 26.57 206.35 163 250 75.7*2042 (1.63) 33.91 299.29 154 275 73.5* 2134 (1.57) 36.52 338.71 155 1:1200 83.3 1736 (1.81) 27.29 223.30 157 250 76.6* 1948 (1.68) 34.92 319.08152 275 — 1943 (1.67) 33.85 — — *Calculated based on weight loss fromadditional stripping.

As the stripping temperature was raised, the molecular weight andkinematic viscosity of the copolymers generally increased, while thepolydispersity and viscosity index generally decreased. The kinematicviscosities at 100° C. were still below 40 cSt, however. The pour pointwas measured for the copolymers of entries 1, 2, 4 and 5 in Table 20,with values of −48° C., −42° C., −45° C. and −39° C., respectively.Although the pour point increased as the stripping temperature wasraised, all of the measured values were relatively low and were withinthe range of −22° C. to −47° C. typically observed for commerciallyavailable high-viscosity poly(alpha olefins).

Example 11 High Viscosity Lubricant Compositions ContainingCopolymerization Products of 1-dodecene and 9-DAME—Effect of PeroxideLoading and Reaction Temperature

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer (9-DAME) in a molar ratio of 9:1, using12 mol %, 14 mol % or 16 mol % di-t-butyl peroxide polymerizationinitiator, and reaction temperatures of 155° C., 165° C. or 175° C. Theinitiator was added in eight portions instead of ten, which decreasedthe reaction time by 1 hour. The copolymerization products were strippedat 200° C. under a vacuum of 1 torr, and then analyzed with regard tokinematic viscosity at 40° C. and 100° C., and viscosity index. Table 21lists the reaction temperature, peroxide loading, reaction yield,kinematic viscosity (KV) at 100° C. and at 40° C., and viscosity indexfor the copolymerization reactions.

TABLE 21 Effects of reaction temperature and di-t-butyl peroxide loadingon yield and viscosity of copolymers formed from a 9:1 molar ratio of1-dodecene and 9-DAME Reaction Initiator KV at KV at 40° C. Temp (° C.)(mol %) Yield (%) 100° C. (cSt) (cSt) VI 155 12 83.6 29.21 238.54 16185.1 30.28 255.75 158 14 89.9 38.85 349.14 162 16 90.1 40.56 367.18 16390.7 41.57 388.25 160 165 14 92.1 40.32 367.50 161 91.7 39.85 359.68 162175 12 59.0 31.66 271.54 158 88.2 33.01 277.00 163 16 95.0 53.74 520.57167 95.7 55.85 550.81 167 94.6 54.29 522.43 169

Copolymers were formed by reacting 1-dodecene and 9-DAME in a differentmolar ratio of 4:1, using 13.4 mol % or 14.5 mol % di-t-butyl peroxidepolymerization initiator, and reaction temperatures of 155° C. or 175°C. The initiator was added in ten portions. The copolymerizationproducts were stripped at 200° C. under a vacuum of 1 torr, and thenanalyzed with regard to kinematic viscosity at 40° C. and 100° C., andviscosity index. Table 22 lists the reaction temperature, peroxideloading, reaction yield, kinematic viscosity (KV) at 100° C. and at 40°C., and viscosity index for the copolymerization reactions.

TABLE 22 Effects of reaction temperature and di-t-butyl peroxide loadingon yield and viscosity of copolymers formed from a 4:1 molar ratio of1-dodecene and 9-DAME Reaction Initiator KV at KV at 40° C. Temp (° C.)(mol %) Yield (%) 100° C. (cSt) (cSt) VI 155 14.5 90.8 40.36 365.11 16191.9 40.20 367.11 161 175 13.4 91.3 35.64 318.16 158 91.1 35.19 306.76161

Copolymers were formed by reacting 1-dodecene and 9-DAME in molar ratiosof 9:1 or 4:1 at a reaction temperature of 175° C., using from 13.5 mol% to 15 mol % di-t-butyl peroxide polymerization initiator. Thecopolymerization products were stripped at 200° C. under a vacuum of 1torr, and then analyzed with regard to kinematic viscosity at 40° C. and100° C., and viscosity index. Table 23 lists the molar ratio ofmonomers, peroxide loading, reaction yield, kinematic viscosity (KV) at100° C. and at 40° C., and viscosity index for the copolymerizationreactions.

The lower viscosities for the copolymers formed at the higher reactiontemperature of 175° C. may have been a result of difficulties inmaintaining this temperature throughout the reaction. The potentialbenefit of using less peroxide initiator at this higher temperatureappeared to come at the expense of obtaining a high kinematic viscosityof 40 cSt. Copolymerizations using 14 mol % peroxide at 165° C. yieldedcopolymers having kinematic viscosity values of from 36.7 to 40.3 cSt(see Table 21, entries 6 and 7), while copolymerizations at 175° C.using the same amount of peroxide (14 mol %) yielded copolymers havinglower kinematic viscosity values of from 37.3 to 38.3 cSt (Table 23,entries 3 and 4). The yields from these two types of copolymerizationwere similar, with the yield of the 14 mol % peroxide/165° C.copolymerizations ranging from 90.8-92.1% and the yield of the 14 mol %peroxide/175° C. combination ranging from 92.3-92.6%.

TABLE 23 Effects of comonomer molar ratio and di-t-butyl peroxideloading on yield and viscosity of 1-dodecene/9-DAME copolymers formed at175° C. 1-dodecene/9- Initiator KV at KV at 40° C. DAME ratio (mol %)Yield (%) 100° C. (cSt) (cSt) VI 9:1 13.7 91.1 38.40 337.63 164 4:1 13.591.1 36.62 316.81 164 13.9 92.3 37.94 332.76 164 14 92.3 37.35 328.70162 92.56 38.32 338.52 163 14.5 92.84 40.46 363.85 163 15 94.0 44.92413.28 165

Example 12 High Viscosity Lubricant Compositions ContainingCopolymerization Products of 1-dodecene and 9-DAME—Effect ofHydrogenation

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer (9-DAME) in molar ratios of 9:1 or 4:1,using from 14.3 to 14.5 mol % di-t-butyl peroxide polymerizationinitiator, and a reaction temperature of 165° C. The copolymerizationproducts were stripped and then analyzed with regard to molecularweight, kinematic viscosity at 40° C. and 100° C., viscosity index, pourpoint and oxidation onset temperature (OOT; ASTM E2009). The 4:1copolymerization yielded 92.0% of a copolymer having a number averagemolecular weight (M_(n)) of 2,498, with a polydispersity index (PDI) of1.93; and the 9:1 copolymerization yielded 91.7% of a copolymer having anumber average molecular weight (M_(n)) of 2,633, with a polydispersityindex (PDI) of 1.87. The copolymers were then hydrogenated to removecarbon-carbon double bonds, and then similarly analyzed. Table 24 liststhe ratio of monomers, peroxide loading, kinematic viscosity (KV) at100° C. and at 40° C., viscosity index, molecular weight, pour point andoxidation onset temperature (OOT) for the copolymers.

TABLE 24 Effects of comonomer molar ratio and hydrogenation on viscosityand pour point of 1- dodecene/9-DAME copolymers formed at 175° C.1-dodecene/ KV (cSt) Pour Point OOT 9-DAME ratio Hydrogenated 100° C.40° C. VI (° C.) (° C.) 4:1 No 39.96 362.46 162 −27 176.5 Yes 41.16 375163 −21 201.4 9:1 No 40.10 359.09 163 −30 170.6 Yes 41.05 371 163 −18200.3

Viscosity and viscosity index were minimally affected by hydrogenation,but the pour point increased with hydrogenation. Hydrogenation improvedoxidative stability of the copolymers as measured by OOT. When thenon-hydrogenated copolymers were blended with 0.5% of adialkyldiphenylamine antioxidant, the OOT increased to over 220° C. foreach copolymer.

Example 13 High Viscosity Lubricant Compositions ContainingCopolymerization Products of 1-dodecene and 9-DAME—Effect of HigherPeroxide Loading and Reaction Temperature

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer (9-DAME) in a molar ratio of 1:1, using14-20 mol % di-t-butyl peroxide polymerization initiator, and reactiontemperatures of 155° C. or 165° C. The copolymerization products wereanalyzed with regard to kinematic viscosity at 40° C. and 100° C., andviscosity index. Table 25 lists the reaction temperature, peroxideloading, reaction yield, kinematic viscosity (KV) at 100° C. and at 40°C., and viscosity index for the copolymerization reactions.

TABLE 25 Effects of reaction temperature and di-t-butyl peroxide loadingon viscosity of copolymers formed from a 1:1 molar ratio of 1-dodeceneand 9-DAME Reaction Initiator KV at KV at 40° C. Temp (° C.) (mol %)Yield (%) 100° C. (cSt) (cSt) VI 155 14 92.52 38.35 351.19 159 16 93.7451.43 515.8 162 16 94.07 55.52 568.3 163 18 95.67 76.83 835.3 172 1996.92 96.77 1087.02 178 20 97.47 150.36 1808.4 194 165 14 90.60 41.24377.37 162 16 95.81 55.59 559.8 166 16 95.86 57.87 591.2 166 18 97.3787.24 954.8 177 19 97.80 117.45 1352.82 185 20 98.30 186.99 2207.0 207

FIG. 8 is a graph of copolymer viscosity as a function of di-t-butylperoxide loading, where the data points are from Table 25. The diamondsymbols in the graph correspond to reaction temperatures of 155° C., andthe square symbols in the graph correspond to reaction temperatures of165° C. The kinematic viscosities at 100° C. of the polymers spanned 38to 186 cSt, and generally increased with increasing initiator loading.

Example 14 High Viscosity Lubricant Compositions ContainingCopolymerization Products of 1-dodecene and 9-DAME—Effect of Two-StageCopolymerization

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer (9-DAME) in a molar ratio of 1:1, using8 mol % or 14 mol % di-t-butyl peroxide polymerization initiator and areaction temperature of 155° C. Portions of the copolymerization productfrom the 8 mol % initiator reaction were subjected to a second stage ofcopolymerization. In the second stage, the copolymerization product wascombined with additional di-t-butyl peroxide polymerization initiatorand heated at 165° C. The additional initiator was added in four dosesat 165° C., and the mixture was then maintained at 165° C. for 4 hours.The amounts of di-t-butyl peroxide polymerization initiator used in thesecond stage copolymerizations were 11.3%, 22.4%, 33.7% or 44.9% of theamount used in the initial copolymerization, which used 8 mol %. Thus,the total amount of initiator used in the two-stage copolymerization inwhich the second stage used 44.9% of the amount of initiator of theinitial copolymerization was equal to the amount of initiator present inthe one-stage copolymerization that used 14 mol % initiator.

The copolymerization products, both from one-stage reactions andtwo-stage reactions, were analyzed with regard to kinematic viscosity at40° C. and 100° C., viscosity index and molecular weight. Table 26 liststhe reaction conditions, reaction yield, kinematic viscosity (KV) at100° C. and at 40° C., viscosity index and molecular weight for thecopolymerization reactions. The reaction yields for the two-stagereactions are overall yields for both stages, as yield for the secondstages were approximately quantitative.

The two-stage reaction with the highest peroxide loading (A+44.9% moreinitiator) gave a kinematic viscosity at 100° C. of 75.16 cSt, which wasgreater than that obtained using the same amount of initiator but in aone-stage reaction (“C”; kinematic viscosity at 100° C.=38.35 cSt).Surprisingly, a viscosity approximately equal to that of this one-stagereaction was obtained by using only half the additional amount ofinitiator, which corresponds to the two-stage reaction identified as “Aproduct+11.3% more initiator” (kinematic viscosity at 100° C.=38.23cSt).

TABLE 26 Effects of two-stage copolymerization on yield, viscosity andmolecular weight of 1:1 1-dodecene/9-DAME copolymers Molecular weightYield KV (cSt) (daltons) Description (%) 100° C. 40° C. VI M_(n) M_(w)PDI 1-step “A”; 69.98 18.68 134.44 157 1579 3021 1.91 8 mol % initiator1-step control “C”; 92.52 38.35 351.19 159 2182 5383 2.47 14 mol %initiator 2-step: A product + 69.89 25.13 199.60 158 1806 3912 2.1711.3% more initiator 2-step: A product + 69.95 38.23 342.50 161 21085508 3.14 22.4% more initiator 2-step: A product + 69.98 54.07 527.85167 2408 7569 3.14 33.7% more initiator 2-step: A product + 69.93 75.16792.29 173 2666 10332 3.88 44.9% more initiator

The viscosities also were surprisingly high in view of the results ofExample 13, above. The two-stage reaction identified as “A product+33.7%more initiator” had a kinematic viscosity at 100° C. of 54.07 cSt. Thisviscosity was similar to those reported in Table 25 for the reactionsthat used 16 mol % initiator at 165° C. (kinematic viscosities at 100°C.=55.59 and 57.87 cSt); however, the two-stage copolymerization used16.4% less initiator than did the one-stage copolymerizations.

Surprisingly, viscosity index was not reduced in the copolymers formedusing the two-stage copolymerizations. It is presently believed thatvolatility of the two-stage products should be less than that of theone-stage products, as low molecular weight species that remain afterthe first stage stripping are likely to react in the second stage.

Example 15 High Viscosity Lubricant Compositions ContainingCopolymerization Products of 1-dodecene and α-ester-alk-ω-enes HavingDifferent Ester Groups

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer in a molar ratio of 4:1, usingapproximately 14 mol % di-t-butyl peroxide polymerization initiator anda reaction temperature of 155° C. The ester group of theα-ester-alk-ω-ene monomer was either methyl (9-DAME), n-pentyl or4-methyl butyl (isomer of n-pentyl). The copolymerization products wereanalyzed with regard to kinematic viscosity at 40° C. and 100° C., andviscosity index. Table 27 lists the peroxide loading, reaction yield,kinematic viscosity (KV) at 100° C. and at 40° C., and viscosity indexfor the copolymerization reactions.

TABLE 27 Effects of ester structure on yield and viscosity of1-dodecene/α-ester-alk-ω-ene copolymers Initiator KV at KV at 40° C.Ester group (mol %) Yield (%) 100° C. (cSt) (cSt) VI methyl 14.0 92.141.67 373.87 165 14.5 94.0 44.93 413.28 165 n-pentyl 14.0 92.8 43.98372.46 175 4-methyl butyl 14.0 93.1 46.55 412.51 172

Surprisingly, the two copolymers formed using pentyl ester comonomershad higher kinematic viscosity (KV) at 100° C. and had higher viscosityindices than the control copolymer formed from 9-DAME comonomer using 14mol % initiator. In addition, the n-pentyl ester comonomer surprisinglyprovided both a higher kinematic viscosity (KV) at 100° C. and a lowerkinematic viscosity (KV) at 40° C. than the control copolymer. It may bedesirable to affect viscosity index while only moderately affectingkinematic viscosity (KV) at 100° C. in lubricant compositions intendedfor use over a range of temperatures, such as automotive lubricants.

Example 16 Low Viscosity Lubricant Compositions Formed by SolutionCopolymerization

Copolymers were formed by reacting an alpha-olefin monomer (1-dodecene)and an α-ester-alk-ω-ene monomer (9-DAME) in the presence of a solvent.

In a first set of copolymerizations, the solvent was decane. Monomermixtures of 1-dodecene and 9-DAME in a 10:1 molar ratio were dilutedwith 25-75 percent by volume (vol %) decane. A 500 mL 3-necked,round-bottom flask equipped with a magnetic stirrer, a N₂ inlet/outlet,a thermometer, a Dean-Stark trap (Note 1) and a condenser was chargedwith 1-dodecene, 9-DAME, di-t-butyl peroxide polymerization initiator,and decane. The monomer mixture was sparged with N₂ gas for 15 minutes.After sparging, the reaction mixture was heated to 150° C. Once attemperature, a second portion of 1.1 mL of initiator was added bysyringe. Every 30 minutes (for a total of 10 additions), another 1.1 mLof initiator was added (a total of 11 mL of initiator). After theaddition of initiator was complete, the reaction mixture was stirred at150° C. for 4 more hours, periodically removing the liquid collected inthe trap. The reaction mixture was then allowed to cool to roomtemperature under nitrogen overnight. The clear product thus obtainedwas transferred to a short path distillation set-up and vacuum-stripped.The mixture was heated to 100° C. slowly under vacuum (2-10 torr), thenheated slowly to 150° C. to remove the residual monomer. The pot residuewas the desired product.

In a second set of copolymerizations, the solvent was PAO6, a branchedisoparaffinic poly(alpha-olefin) having a kinematic viscosity at 100° C.of 6 cSt. A 250 mL 3-necked, round-bottom flask equipped with a magneticstirrer, a N₂ inlet/outlet, a thermometer and a condenser was chargedwith 1-dodecene, 9-DAME and PAO6. The reaction mixture was sparged withnitrogen gas for 1 hour to overnight. After sparging, the monomermixture was heated to 150° C. Once at temperature, 0.62 mL of di-t-butylperoxide polymerization initiator was added by syringe. Every 30 minutesfollowing the initial addition of initiator, another 0.62 mL was addedfor 4.5 hours. After the addition of initiator was complete, thereaction mixture was stirred at 150° C. for 4 more hours, periodicallyremoving the liquid collected in the trap. After 8.5 hours, the reactionmixture was allowed to cool to room temperature under nitrogen. Theclear product thus obtained was transferred to a short path distillationset-up and vacuum-stripped. The mixture was heated to 200° C. slowlyunder vacuum (2-10 torr) to remove the residual monomer. While warm(approximately 70-100° C.), the product was filtered using a mediumcoarseness paper filter or a coarse filter.

The copolymerization products were analyzed with regard to kinematicviscosity at 100° C., and product yields. Table 28 lists the reactants,solvent, reaction yield, and kinematic viscosity (KV) at 100° C. for thecopolymerization reactions.

TABLE 28 Effects of solvent on yield and viscosity of 1-dodecene/9-DAMEcopolymers 1-dodecene/9- Initiator Amount of Yield KV at 100° C. DAMEratio (mol %) Solvent solvent (%) (cSt) 10:1  9.1 — — 79 28 10:1  9.1decane 25 vol % 68 16 40 vol % 76 12.2 75 vol % 77 9.1 75 vol % 78 8.755:2 8.5 PAO6 30 wt % 64 9.96 4:3 30 wt % 76 12.3 4:3 40 wt % 71 9.11

In the copolymerizations using decane as the solvent, the lessconcentrated reaction mixtures provided higher comonomer conversions andalso lower viscosities than comparable copolymerizations performed neat.Surprisingly, a yield of 78% was obtained in the copolymerization using75 vol % decane, and the kinematic viscosity at 100° C. was below 10cSt. In the copolymerizations using PAO6 as the solvent, dilutions of 30to 36 wt % provided kinematic viscosities at 100° C. of approximately 10cSt, particularly when the amount of 9-DAME is lower.

While various embodiments of the invention have been described, it willbe apparent to those of ordinary skill in the art that other embodimentsand implementations are possible within the scope of the invention.Accordingly, the invention is not to be restricted except in light ofthe attached claims and their equivalents.

1. A lubricant composition, comprising: a copolymer comprisingconstitutional units formed from monomers, the monomers comprising afirst alpha-olefin having from 8 to 10 carbon atoms, and anα-ester-alk-ω-ene molecule; where the composition has a kinematicviscosity at 100° C. of from 5 to 20 centistokes.
 2. The lubricantcomposition of claim 1, where the first alpha-olefin comprises 1-decene.3. The lubricant composition of claim 1, where the α-ester-alk-ω-enemolecule comprises 9-decenoic acid methyl ester.
 4. The lubricantcomposition of claim 1, where the α-ester-alk-ω-ene molecule is selectedfrom the group consisting of 9-decenoic acid methyl ester, 9-decenoicacid ethyl ester, 9-decenoic acid propyl ester, 10-undecenoic acidmethyl ester, 10-undecenoic acid ethyl ester, 10-undecenoic acid propylester, 11-dodecenoic acid methyl ester, 11-dodecenoic acid ethyl ester,and 11-dodecenoic acid propyl ester.
 5. The lubricant composition ofclaim 1, where the monomers further comprise a second alpha-olefinhaving from 8 to 16 carbon atoms; where the molar ratio of the firstalpha-olefin to the second alpha-olefin is at least 2:1.
 6. Thelubricant composition of claim 1, where the monomers further comprise atleast one unsaturated monomer selected from the group consisting ofethylene, a styrene, a halogenated vinyl compound, an acrylate, anacrylamide, acrylonitrile, N-vinyl pyrrolidone; an alpha-alkenol, analpha-alkenyl acetate, an alpha-alkenyl halide, allyl cyclohexane, allylcyclopentane, and substituted derivatives thereof.
 7. The lubricantcomposition of claim 1, where the composition further comprises at most50 wt % of a lubricant additive.
 8. The lubricant composition of claim1, where the composition has a kinematic viscosity at 100° C. of from 10to 15 centistokes.
 9. A method of forming a lubricant composition,comprising: forming a reaction mixture comprising a first monomercomprising an alpha-olefin having from 8 to 10 carbon atoms, and asecond monomer comprising an α-ester-alk-ω-ene molecule; and forming aproduct mixture comprising a copolymer comprising constitutional unitsformed from the first and second monomers; where the composition has akinematic viscosity at 100° C. of from 5 to 20 centistokes.
 10. Themethod of claim 9, where the reaction mixture further comprisesdi-t-amyl peroxide.
 11. The method of claim 9, where the reactionmixture further comprises a chain-transfer agent selected from a thiolcompound and a halide compound. 12.-31. (canceled)